Steve Holmes University of Strathclyde Computer Centre Curran Building 100 Cathedral Street Glasgow
Please note: Steve no longer works for the University of Strathclyde, and we are unable to answer queries relating to this course. You are welcome to make links to it however, but please bear in mind that it was written for students within the University and so some parts may not be relevant to external readers.
This course was awarded a NetGuide Gold Award during the 1990s.
Ammeraal, L., Programs And Data Structures In C, Wiley, 1987. Berry, J. T., Advanced C programming, Prentice-Hall, 1986. Berry, R. E. and Meekings B.A.E., A book on C, Macmillan, 1984. Barkakati, N., The Waite Group's essential guide to ANSI C, H.W. Sams, 1988. Bolon, C., Mastering C, Sybex, 1986. Brown, D.L., From Pascal to C : an introduction to the C programming language, Wadsworth Pub. Co., 1985. Brown, T. D., C for BASIC programmers, Silicon Press, 1987. Chapman, A., Mastering C programming, Macmillan Educational, 1991. Chirlian, P.M., Programming in C++, Merrill Pub. Co., 1990. Darnell, P.A. and Margolis, P.E., Software Engineering In C, Springer-Verlag, 1988. Darnell, P.A., C : A Software Engineering Approach, 2nd ed., Springer-Verlag, 1991. Davis, S.R., C++ programmer's companion : designing, testing, and debugging, Addison-Wesley, 1993. Eliason, A.L., C, A Practical Learning Guide, Science Research Associates, 1988. Ezzell, B., Turbo C++ Programming: An Object-Oriented Approach, Addison-Wesley, 1990. Ezzell, B., Borland C++ 3.0 Programming, 2nd ed., Addison-Wesley Pub. Co., 1992. Farmer, M., The Intensive C Course, Studentlitteratur, 1987. Flamig, B., Turbo C++ - A Self-Teaching Guide, Wiley, 1991. Flamig, B., Practical Data Structures In C++, Wiley, 1993. Goldenthal, N., Turbo C Programmer's Guide, Weber Systems, 1987. Gonnet, G. H. and Baeza-Yates, R., Handbook Of Algorithms And Data Structures In Pascal And C, 2nd ed., Addison-Wesley Pub. Co., 1991. Hancock, L. and Krieger, M., The C primer, McGraw-Hill, 1982. Hansen, A., C programming : a complete guide to mastering the C language, Addison-Wesley, 1989. Hansen, T.L., The C++ Answer Book, Addison-Wesley, 1990. Harbison, S.P. and Steele, G.J., C, A Reference Manual, Prentice-Hall, 1984. Holub, A.I., The C companion, Prentice-Hall, 1987. Ince, D., Object-Oriented Software Engineering With C++, McGraw-Hill Book Co., 1991. Jaeschke, R., Portability And The C Language, 1st ed., Hayden Books, 1989. Jones, R. and Stewart, I., The Art Of C Programming, Springer-Verlag, 1987. Kay, J. and Keummerfield, R., C programming in a UNIX environment, Addison-Wesley, 1989. Kelley, A. and Pohl, I., C By Dissection : The Essentials Of C Programming, Benjamin/Cummings Pub. Co., 1987. Kelley, A. and Pohl, I., A book on C: programming in C, 2nd ed., Benjamin/Cummings Pub. Co., 1990. Kelley, A. and Pohl, I., Turbo C: the essentials of C programming, Benjamin/Cummings Pub. Co., 1988. Kernighan, B.W. and Ritchie, D.M., The C Programming Language, Prentice Hall, 1988. Kochan, S. G., Programming in C, Hayden Book Co., 1983. Koenig, A., C Traps And Pitfalls, Addison-Wesley, 1989. Korsh, J.F., Data Structures, Algorithms, And Program Style Using C, PWS-KENT Pub. Co., 1988. Lafore, R.W., The Waite Group's object-oriented programming in Turbo C++, Waite Group Press, 1991. Ledgard, H. F., C With Excellence : Programming Proverbs, Hayden Books, 1987. Lewin, M.H., Elements of C, Plenum Press, 1986. Maguire, S.A., Writing Solid Code: Microsoft Techniques For Developing Bug-Free C Programs, Microsoft Press, 1993. McCord, J., Borland C++ 3.1 Programmer's Reference, 2nd ed., Que, 1992. Muldner, T. and Steele, P.W., C As A Second Language: For Native Speakers Of Pascal, Addison-Wesley, 1988. McBride, P. K., C Clearly : An Introduction To C Programming, Blackwell Scientific Publications, 1993. Purdum, J.J. C Programming Guide, Que Corp., 1985. Oualline, S., Practical C Programming, Reilly & Associates, 1991. Plauger, P. J., The Standard C Library, Prentice Hall, 1992. Purdum, J.J., PC Magazine Guide To C Programming, Ziff-Davis Press, 1992. Rabinowitz, H. and Schaap, C., Portable C, Prentice Hall, 1990. Ranade, J. and Nash, A., The Elements Of C Programming Style, McGraw-Hill, 1993. Schildt, H., Advanced C, Osborne McGraw-Hill, 1986. Schildt, H., Advanced Turbo C, Osborne McGraw-Hill, 1987. Schildt, H., C: The Complete Reference, Osborne McGraw-Hill, 1990. Schildt, H., The Art Of C: Elegant Programming Solutions, Osborne McGraw-Hill, 1991. Sedgewick, R., Algorithms In C, Addison-Wesley Pub. Co., 1990. Sedgewick, R., Algorithms In C++, Addison-Wesley Pub. Co., 1992. Shammas, N.C., Introducing C To Pascal Programmers, Wiley, 1988. Smith, J.D., Reusability And Software Construction: C and C++, Wiley, 1990. Spuler, D., Comprehensive C, Prentice Hall, 1992. Swartz, R., Doing Business With C, Prentice Hall, 1989. Tenenbaum, A. M., Langsam, Y. and Augenstein, M.J., Data Structures Using C, Prentice Hall, 1990. Traister, R.J., Going From BASIC To C, Prentice-Hall, 1985. Van Wyk, C.J., Data Structures and C programs, Addison-Wesley, 1988. Waite, M. and Prata, S., C: Step-By-Step, H.W. Sams, 1989. Winder, R., Developing C++ software , J. Wiley, 1991. Woollard, R., The Waite Group's Master C++: Let The PC Teach You Object-Oriented Programming, Waite Group Press, 1992.
The UNIX operating system is a popular Operating system because of its simplicity in its design and functioning. The following are the key features which made the UNIX OS very popular: • Multiuser system • Time sharing • Portability • Multitasking • Background processing • Hierarchical file system • Security and Protection • Better communication • Availability of compilers / tools / utilities • Shell programming.
KERNEL AND THE SHELL
The main control program in a UNIX operating system is called the kernel. However, the kernel does not allow the user to give its commands directly; instead when the user types commands on the keyboard they are read by another program in the Operating System called a shell which parses, checks, translates and then passes them to the kernel for execution.
There are a number of different shells available, with names such as sh, csh, tcsh, ksh, bash, each with different rules of syntax; these are partly though not completely responsible for the diversity of UNIX. Later in our discussion we will see what are the criteria to select a shell. Once the command has been interpreted and executed, the kernel sends its reply, which may simply be a prompt for the next command to be entered, either directly to the display monitor. This is a program responsible for deciding where and in what form the output will appear on the display monitor. If for any reason the kernel cannot perform the command requested (wrong syntax), for example, the reply will be an error message; the user must then re-enter the corrected command.
UNIX COMMANDS
With many competing standards (UNIX 98, UNIX95, POSIX.2, SVID3, 4.3BSD, etc.) and most users having to deal with multiple systems, it’s crucial to know which commands are important enough to be used on nearly every version of UNIX. The following is a list of commonly used commands which are organised under different categories for understanding and ease of use. Keys proceeded by a ^ character are CONTROL key combinations.
Terminal Control Characters
^h backspace erase previously typed character ^u erase entire line of input so far typed ^d end-of-input for programs reading from terminal ^s stop printing on terminal ^q continue printing on terminal ^z currently running job; restart with bg or fg DEL, ^c kill currently running program and allow clean-up before exiting ^\ emergency kill of currently running program with no chance of cleanup
Login and Authentication
login access computer; start interactive session logout disconnect terminal session passwd change local login password; you MUST set a non-trivial password
Information date show date and time history list of previously executed commands pine send or receive mail messages msgs display system messages man show on-line documentation by program name info on-line documentation for GNU programs w, who who is on the system and what are they doing who am i who is logged onto this terminal top show system status and top CPU-using processes uptime show one line summary of system status finger find out info about a user@system
File Management
cat combine files cp copy files ls list files in a directory and their attributes mv change file name or directory location rm remove files ln create another link (name) to a file chmod set file permissions des encrypt a data file with a private key find find files that match specified criteria
Display Contents of Files
cat copy file to display device vi screen editor for modifying text files more show text file on display terminal with paging control head show first few lines of a file(s) tail show last few lines of a file; or reverse line order grep display lines that match a pattern lpr send file to line printer pr format file with page headers, multiple columns etc. diff compare two files and show differences cmp compare two binary files and report if different od display binary file as equivalent octal/hex codes file examine file(s) and tell you whether text, data, etc. wc count characters, words, and lines in a file
Directories
cd change to new directory mkdir create new directory rmdir remove empty directory (remove files first) mv change name of directory pwd show current directory
Devices
df summarize free space on disk device du show disk space used by files or directories
Special Character Handling for C-shell
* match any characters in a file name ~user shorthand for home directory of "user" $ name substitute value of variable "name" \ turn off special meaning of character that follows ‘ In pairs, quote string w/ special chars, except ! “ In pairs, quote string w/ special chars, except !, $ ` In pairs, substitute output from enclosed command
Controlling Program Execution for C-shell
& run job in background DEL, ^c kill job in foreground ^z suspend job in foreground fg restart suspended job in foreground bg run suspended job in background ; delimit commands on same line ( ) group commands on same line
DESCRIPTION OF COMMONLY USED UNIX COMMANDS
The description for the most commonly used UNIX commands is given below in an alphabetic order.
cat
cat allows you to read multiple files and then print them out. You can combine files by using the > operator and append files by using >>. Syntax: cat [argument] [specific file] Example: cat abc.txt If you want to append three files (abc.txt, def.txt, xyz.txt), give the command as, cat abc.txt def.txt xyz.txt > all
cd, chdir
cd (or chdir) stands for “change directory”. This command is the key command to move around your file structure. Syntax: cd [name of directory you want to move to] When changing directories, start with / and then type the complete file path, like cd /vvs/abc/xyz
chmod
chmod (which stands for “change mode”) changes who can access a particular file. A “mode” is created by combining the various options from who, opcode, and permission. Syntax: chmod [option] mode file If you look at a list of files using the long list command ls –l, you’ll see the permissions, owner, file size, modification time, and filename. The first column of the list shows who can read, write, and execute the files or directories, in other words, the permissions. It basically shows who has permission to do what to a given file or directory. r stands for “read” and means that you’re allowed to read the file or directory. w stands for “write” and gives permission to edit or change the file as well as create, move, rename, or remove a directory. x stands for “execute” which gives permission to run a file or search a directory. Every file or directory has four sets of rwx permissions. The first set represents the user (u), the second set represents the group (g), the third set represents other (o), and the fourth set represents all (a). The column will look like this: rwxrwxrwx Each set of rwx represents user, group, and other respectively. Only the owner of a file or a privileged user may change the permissions on a file. There are two ways to change permissions on a file or directory, either numerically or by using lettered commands. Both ways use the command chmod. To add permissions to a file, you use +, to remove permissions you use-. For example, take a file: -rw-r--r-- 1 yash mony 476 Apr 14 17:13 vvs.txt To allow a group (mony, in this case) “write” access, you would type: chmod g+w vvs.txt If you wanted to remove “read” ability from “other” you would type: chmod o-r vvs.txt It is also possible to specify permissions using a three-digit sequence. This is a more efficient way to change permissions (or at least it requires less typing), so use this method if it doesn’t confuse you. Each type of permission is given an octal value. Read is given the value of 4, write is given the value of 2, and execute is given the value of 1. These values are added together for each user category. The permissions are changed by using a three-digit sequence with the first digit representing owner permission, the second digit representing group permission, and the third digit representing other permission. For example, if you wanted to make vvs.txt readable, writable, and executable for the user, readable and writable for the group, and readable for other, you would type: chmod 764 vvs.txt The first digit means readable and writable for the user (4+2+1), the second digit means readable and writable for the group (4+2+0), and the third digit means readable for other (4+0+0). If you want to change the permissions on a directory tree use the -R option. chmod -R will recursively change the permissions of directories and their contents.
chown
chown changes who owns a particular file or set of files. New owner files refer to a user ID number or login name that is usually located in the /etc/password directory. The owner of a file or directory can be seen by using the command. Syntax: chown [option] newowner files Only the owner of a file or a privileged user can change the permissions on a file or directory. The following example changes the owner of vvs.txt to sridhar chown sridhar vvs.txt
cp
The cp command copies files or directories from one place to another. You can copy a set of files to another file, or copy one or more files under the same name in a directory. If the destination of the file you want to copy is an existing file, then the existing file is overwritten. If the destination is an existing directory, then the file is copied into that directory. Syntax: cp [options] file1 file2 If you want to copy the file favourites.html into the directory called laksh, you give the command as: cp favourites.html /vvs/laksh/ A handy option to use with cp is -r. This recursively copies a particular directory and all of its contents to the specified directory, so you won’t have to copy one file at a time.
date
The date command can be used to display the date or to set a date. Syntax: date [option] [+format] date [options] [string] The first structure shows how date can be used to display the current date. A certain format can be specified in which the date should be displayed. Check the Unix manual for specific formats and options. The second structure allows you to set the date by supplying a numeric string. Only privileged users will be able to use this second command structure.
diff
diff displays the lines that differ between two given files. Syntax: diff [options] [directory options] file1 file2 diff can be an extremely valuable tool for both checking errors and building new pages. If you run a diff between two files, you'll be shown what differences the files have line by line. The lines referring to file1 are marked with the <> symbol. If the file is a directory, diff will list the file in the directory that has the same name as file2. If both of the files are directories, diff will list all the lines differing between all files that have the same name. If you have a file that is not working properly, it can be a great help to check it against a similar file that is working. It will often quickly alert you to a line of code that’s missing. A handy option to use if you want to generally compare two files without noting the complex differences between them is the -h option (h stands for half-hearted). Using -i as an option will ignore differences in uppercase and lowercase characters between files, and -b will ignore repeating blanks and line breaks.
exit
The exit command allows you to terminate a process that is currently occurring. For example, if you wanted to leave a remote host that you were logged onto (see rlogin also), you should type exit. This would return you to your home host.
find
find searches through directory trees beginning with each pathname and finds the files that match the specified condition(s). You must specify at least one pathname and one condition. Syntax: find pathname(s) condition(s) There are several handy conditions you can use to find exactly what you want. The -name condition will find files whose names match a specified pattern. The structure for the name condition is: find pathname -name pattern The condition -print will print the matching files to the pathname specified. -print can also be used in conjunction with other conditions to print the output. If you wanted to find all the files named favorites.html in the directory Ram, then you’d do this: find /Ram -name favorites.html –print This looks through the directory Ram and finds all the files in that directory that contain favorites.html, then prints them to the screen. Your output would look like this: /Ram/sixteen_candles/favorites.html /Ram/favorites.html /Ram/breakfast_club/favorites.html All meta-characters (!, *, ., etc.) used with -name should be escaped (place a \ before the character) or quoted. Meta-characters come in handy when you are searching for a pattern and only know part of the pattern or need to find several similar patterns. For example, if you are searching for a file that contains the word “favorite”, then use the meta-character * to represent matching zero or more of the preceding characters. This will show you all files which contain favorite. find /Ram -name '*favorite*' -print This looks through the directory Ram and finds all the files in that directory that contain the word “favorite”. The output would look like this: /Ram/sixteen_candles/favorites.html /Ram/favorites.html /Ram/least_favorites.html /Ram/breakfast_club/favorites.html /Ram/favorite_line.html The -user condition finds files belonging to a particular user ID or name.
finger
finger displays information about various users as well as information listed in the .plan and .project files in a user’s home directory. You can obtain the information on a particular user by using login or last names. If you use the latter, the info on all users with that last name will be printed. Environments that are hooked up to a network recognize arguments (users) in the form of user@host or @ host. Syntax: finger [options] users
grep
The grep command searches a file or files for lines that match a provided regular expression (“grep” comes from a command meaning to globally search for a regular expression and then print the found matches). Syntax: grep [options] regular expression [files] To exit this command, type 0 if lines have matched, 1 if no lines match, and 2 for errors. This is very useful if you need to match things in several files. If you wanted to find out which files in our vvs directory contained the word “mca” you could use grep to search the directory and match those files with that word. All that you have to do is give the command as shown: grep ‘mca’ /vvs/* The * used in this example is called a meta-character, and it represents matching zero or more of the preceding characters. In this example, it is used to mean “all files and directories in this directory”. So, grep will search all the files and directories in vvs and tell you which files contain “mca”. head
head prints the first couple of lines of one or multiple files. -n is used to display the first n lines of a file(s). The default number of lines is 10. Syntax: head [-n] [files] For example, the following command will display the first 15 lines of favourites.html. head -15 favourites.html kill
kill ends the execution of one or more process ID’s. In order to do this you must own the process or be designated a privileged user. To find the process ID of a certain job give the command ps. Syntax: kill [options] PIDs There are different levels of intensity to the kill command, and these can be represented either numerically or symbolically. kill -1 or HUP makes a request to the server to terminate the process, while kill -9 or kill KILL forces a process to terminate absolutely. Most politely, UNIX users will attempt to kill a process using -1 first before forcing a process to die. less
less is similar to more in that it displays the contents of files on your screen. Unlike more, less allows backward and forward movement within the file. It does not read the whole file before displaying its contents, so with large files less displays faster than more. Press h for assistance with other commands or q to quit. Syntax: less [options] [files]
lprm
lprm removes printer queue requests. Syntax: lprm /usr/ucb/lprm [optons] [job#] [users] The lprm command will remove a job or jobs from a printer’s queue. If lprm is used without any arguments, it will delete the active job if it is owned by the user. If the command is used with -, then all the jobs owned by the user will be removed. To remove a specific job, use the job number.
ls
ls will list all the files in the current directory. If one or more files are given, ls will display the files contained within “name” or list all the files with the same name as “name”. The files can be displayed in a variety of formats using various options. Syntax: ls [options] [names] ls is a command you'll end up using all the time. It simply stands for list. If you are in a directory and you want to know what files and directories are inside that directory, type ls. Sometimes the list of files is very long and it flies past your screen so quickly you miss the file you want. To overcome this problem give the command as shown below: ls | more The character | (called pipe) is typed by using shift and the \ key. | more will show as many files as will fit on your screen, and then display a highlighted “more” at the bottom. If you want to see the next screen, hit enter (for moving one line at a time) or the spacebar (to move a screen at a time). | more can be used anytime you wish to view the output of a command in this way. A useful option to use with ls command is -l. This will list the files and directories in a long format. This means it will display the permissions (see chmod), owners, group, size, date and time the file was last modified, and the filename. drwxrwxr-x vvs staff 512 Apr 5 09:34 sridhar.txt -rwx-rw-r-- vvs staff 4233 Apr 1 10:20 resume.txt -rwx-r--r-- vvs staff 4122 Apr 1 12:01 favourites.html There are several other options that can be used to modify the ls command, and many of these options can be combined. -a will list all files in a directory, including those files normally hidden. -F will flag filenames by putting / on directories, @ on symbolic links, and * on executable files. man
The man command can be used to view information in the online Unix manual. Syntax: man [options] [[section] subjects] man searches for information about a file, command, or directory and then displays it on your screen. Each command is a subject in the manual. If no subject is specified, you must give either a keyword or a file. You can also search for commands that serve a similar purpose. For example, if you want more information about the chmod command, you should type: man chmod A screen will then appear with information about chmod. Type q to quit. mkdir
mkdir creates a new directory. Syntax: mkdir [options] directory name For example, to create a directory called parkhyath in the present working directory, give the command as, mkdir prakhyath more
more displays the contents of files on your screen. Syntax: more [options] [files] To have the next line displayed, hit the return key, otherwise press the spacebar to bring up the next screen. Press h for assistance with other commands, n to move to the next file, or q to quit. mv
mv moves files and directories. It can also be used to rename files or directories. Syntax: mv [options] source target If you wanted to rename vvs.txt to vsv.txt, you should give the command as: mv vvs.txt vsv.txt After executing this command, vvs.txt would no longer exist, but a file with name vsv.txt would now exist with the same contents. passwd
The passwd command creates or changes a user’s password. Only the owner of the password or a privileged user can make these changes. Syntax: passwd [options] files ps
The ps command prints information about active processes. This is especially useful if you need to end an active process using the kill command. Use ps to find out the process ID number, then use kill to end the process. Syntax: ps [options] pwd
pwd prints the pathname of the current directory. If you wanted to know the path of the current directory you were in you give the command as pwd. You will get the complete path. rlogin
The rlogin command, which stands for remote login, lets you connect your local host to a remote host. Syntax: rlogin [options] host If you wanted to connect to the remote host vsmanyam and you were on sree, you would do this: rlogin vsmanyam password:****** You would then be at vsmanyam
rm
rm removes or deletes files from a directory. Syntax: rm [options] files In order to remove a file, you must have write permission to the directory where the file is located. While removing a which does’t have write permission on, a prompt will come up asking you whether or not you wish to override the write protection. The -r option is very handy and very dangerous. -r can be used to remove a directory and all its contents. If you use the -i option, you can possibly catch some disastrous mistakes because it’ll ask you to confirm whether you really want to remove a file before going ahead and doing it.
rmdir
rmdir allows you to remove or delete directories but not their contents. A directory must be empty in order to remove it using this command. Syntax: rmdir [options] directories If you wish to remove a directory and all its contents, you should use rm -r.
su
su stands for superuser (a privileged user), and can be used to log in as another user. If no user is specified and you know the appropriate password, su can be used to log in as a superuser. Syntax: su [option] [user] [shell_args]
tail
The tail command will print the last ten lines of a file. tail is often used with the option -f, which tells tail not to quit at the end of file and instead follow the file as it grows. Syntax: tail [options] [file] Use ctrl-c to exit this command.
telnet
You can communicate with other computers by using the telnet protocol. The host must be a name or an Internet address. telnet has two modes: the command mode, which is indicated by the telnet > prompt, and an input mode which is usually a session where you would log on to the host system. The default mode is command mode, so if no host is given it will automatically go into this mode. If you need help while in the command mode, type? or help. Syntax: telnet [host [port]]
who
The who command prints out information about the most recent status of the system. If no options are listed, then all of the usernames currently logged onto the system are displayed. Syntax: who [options] [file] The option am i will print the name of the current user. The -u option will display how long the terminal has been idle.
Q.1a)With two examples from industry, explain the role of science in production process.
Ams:Most of the production processes used for most of the products and services generated in the industry, and even in homes is the result of application of theories and principles of science.
For example, let us take the ubiquitous electricity. The knowledge electricity itself we have today is the result of efforts of science. The equipments we use for generate electricity like the modern turbines and generators also cannot be designed, manufactured or operated without modern scientific knowledge.
Within homes let us take the process of washing clothes, The process appears quite simple to us. But the shapes of various components that make the clothes move in different ways so that these are cleaned thoroughly, and the movement of these components has been designed based on very specialized scientific knowledge.
The humble knife you use in the kitchen is most probably made of steel that has been developed and manufactured based on very specialized scientific knowledge. Even the water that you get in your tap is transported from its source to your tap employing a complicated network of pipes, pumps and storage tanks, which have been designed using scientific knowledge of hydraulics. It between the water has been purified using a combination of processes such as filtration, flocculation, and chemical reactions. We need science to understand and use all such processes to use them to serve our needs.
As a matter of fact it will be difficult for us to find a modern production process in which science does not play an important role.
b)Discuss the achievements in the areas of quantitative science and transport during Bronze age.
Ans: Quantitative Science:
With the availability of surplus in agriculture and the production of non-agricultural goods by craftsmen, exchange and trade became a part of life. With the passing of time, exchange dealt with increasingly different types of commodities as well as increasingly large quantities of these commodities. Therefore, what should be exchanged, with what, and in what quantity, could no longer be simply memorized. Some standards, such as numbers and measures of amounts of grain etc. and weights, became necessary so that proper quantities of goods could be set apart or marked off for collection and exchanged.
For the record, the symbol for measure was followed by a picture or shorthand symbol of the particular object which was to be traded. Gradually, symbols were introduced to cover actions as well as objects, and so writing emerged. Writing developed, either as a sketched symbol standing for a whole idea as in Chinese or symbols and sounds going together as in Mesopotamian cuneiform or the Egyptian hieroglyphic. The standardization of exchange in the form of weight led to the use of balance, a scientific invention of great consequence. Exchange also necessitated simple calculations such as addition and subtraction of numbers which led to arithmetic.
The ability to count and calculate found immediate use in certain other areas such as making of calendars and in the consequent development of astronomy.
Transport:
At some early date, the sail was invented making the first use of inanimate power for locomotion. When river transport was extended to the sea, it posed new problems of boat construction and navigation. Stronger winds meant stronger fabrics for making a sail, and construction of heavy frames and structure to hold them. Woodwork had to be very strong and durable too. The river went in a known direction, it was like a road, but one could easily lose one’s way on the high seas. New ways of finding location and direction had to be searched.
The rise of cities would also have required heavy to be transported over short distances by land. This may have been done by the use of sledges to begin with. Heavy sledges could be eased downhill. However, along the plains, tree trunks came in handy as rollers the discovery of wheel revolutionized land transport, it is not possible for us to say, from historic evidence, where the wheel was first invented. It is used for making carts which transported goods and passengers was possibly one of the most significant developments of the Bronze Age.
Q.2a)Briefly discuss the developments in mathematics and astronomy during Gupta period in India.(5)
Ans:Not only in the traditional Sanskrit literature or in the field of other worldly literature but changes came in the over all social life in the Gupta period with the tremendous development of science during this period. With the growth and intensification in the arena of mathematics, astrology, astronomy, medicine, Chemistry, Metallurgy, Botany, Zoology and Engineering Gupta period gained a striking facet.
Mathematics:
In ancient India, mathematics was treated as a handmaid to astronomy. But Aryabhata treated this as an independent subject. He wrote his work Aryabhtiyam at Pataliputra in 499 A.D. He was the first scholar to discover the decimal system of place values. He has given all his results in the form of finished formulas. Regarding geometry he discussed his work with the area of a triangle, the theorem on similarity of triangles, the area of a circle and the theorem relating to rectangles contained by the segments of chords or a circle. In algebra he discusses the rule of three and a rule for solving examples concerning interest. He has also discussed other mathematical subjects such as arithmetical progression and a formula for the sum of squares and the cubes of natural numbers.
Astronomy:
In Astronomy, Aryabhata was the first to assert that the earth rotates round its axis. He was the first person to utilize sine functions in astronomy. He also calculated the increase and decrease in two consecutive days, he stated calculating accurately the angular diameter of the earth`s shadow at the moon`s orbit and gave a method of finding the duration of an eclipse. These were all new things for the nation as till then they believe in another world.
Varahamihira was another important astronomer of the Gupta period. Most probably he began composing his work Panchasiddhahtika in 505 A.D. He discusses in this work the principles of the five astronomical schools, which were considered as the most authoritative one in his time. Of these five schools the Romaka Siddhanta clearly betrays Western influence. This is expected to happen as a result of active trade contacts between the Roman Empire and the Gupta Empire. The Surya Siddhanta is the most important and complete astronomical work of the period. It seems that Greek astronomy served as the basis of the Surya-siddhahta. The other three schools of astronomy discussed by Varahamihira are the Paitamaha Siddhahta, the Vasistha Siddhahta, and the Paulish Siddhanta. In his work Varahamihira has preserved the essential teachings of these five schools of astronomy, which is a great collection of work.
b)Compare the state of science and technology during Renaissance with that of post Renaissance period in Europe.(5)
Ans:Renaissance:
Science and art were very much intermingled in the early Renaissance, with artists such as Leonardo da Vinci making observational drawings of anatomy and nature. Yet the most significant development of the era was not a specific discovery, but rather a process for discovery, the scientific method. This revolutionary new way of learning about the world focused on empirical evidence, the importance of mathematics, and discarding the Aristotelian "final cause" in favor of a mechanical philosophy. Early and influential proponents of these ideas included Copernicus and Galileo.The new scientific method led to great contributions in the fields of astronomy, physics, biology, and anatomy. With the publication of Vesalius's De humani corporis fabrica, a new confidence was placed in the role of dissection, observation, and a mechanistic view of anatomy.
Post-Renaissance
By the mid-1700s Science was beginning to get more sophisticated. French chemist Antoine-Laurent Lavoisier was most influential in developing an experimental approach, laid the foundation of modern chemistry. In 1789, Lavoisier published a list of pure substances. By the early 1800s, John Dalton's atomic theory and the concept of atomic weights developed. In 1829 Johann Döbereiner noted that there were triplets of elements in which the central species' properties were almost exactly midway between the outer two. In 1860 Stanislao Cannizzaro presented analyses at an international chemistry meeting that, when merged with previously ridiculed hypotheses by fellow Italian Amedeo Avogadro, yielded unambiguous atomic weights.
Q.3a)With the help of a suitable example, explain how scientific approach can help solve personal problems.(5)
Ans: Scientific method refers to bodies of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering observable, empirical and measurable evidence subject to specific principles of reasoning. A scientific method consists of the collection of data through observation and experimentation, and the formulation and testing of hypotheses.
What is a personal problem? The individual is hesitant to discuss the problem with others including his family members. for example let us take a person afflicted by Hepatitis B. The person does not want to reveal it to anyone but is worried that he may infect his partner if he has sex. How does scientific method help solve this problem?
Scientific studies have proved that it is a sexually transmitted disease and there is no effective cure. There is a lot of research being done on this subject and the person can consult his doctor with the assurance that he will get an advice backed by scientific research. Since scientific studies are based on observations which can be repeated, the person can see for himself/herself the effects of the studies. Gathering information from scientific sources is more reliable than opinions of individuals alone.
b)Describe Kepler’s laws related to planetary motion.(5)
Ans:
Kepler’s 1st law:
(1) Planets move around the Sun in ellipses, with the Sun at one focus.
Orbital movement of Earth and Mars around the Sun
Kepler's 2nd law:
(2) The line connecting the Sun to a planet sweeps equal areas in equal times.
Illustrating Kepler's 2nd law: segments AB and CD take equal times to cover.
Kepler's 3rd Law:
(3) The square of the orbital period of a planet is proportional to the cube of the mean
distance from the Sun.
Let the mean distance of planet from Sun is r and its orbital period is T, then
T2 ∞r3
Q.4a)How have optical astronomy and radio astronomy aided in the study of universe?(5)
Ans: Optical astronomy contributed a lion's share to our knowledge of Universe around Earth as of now . Interior of astronomical bodies revealed itself in Spectroscopic studies. Further refinements culminating in measurement of Red shift resulted in the knowledge about the extent of universe due to Hubble's efforts. It also gave clues to the past as light reaching us now must have started years ago or even a million years ago. It gave us the chronology of Universal events.
Then JC Maxwell combined all known laws of electricity & magnetism into a set of 4 equations and derived an expression for speed of Electro magnetic waves. He conjectured that 'these (EM waves) have same speed as that of light waves'. It was established then, that light is a mere sliver in the vast electromagnetic spectrum. Now the activity started to 'see' universe through different parts of the EM spectrum. This thinking led Jansky to conjecture that the noise he heard on radio was actually the emission from the heavenly bodies in sky, just as light that reaches us on Earth. Using well-refined techniques of radio reception more sensitive receiving systems were deviced. The chief feature in these is the sharpness of the beam so that energy from a tiny solid angle can be picked up for energy reception. Antenna systems were designed for that, along with reception methods with devices that add less noise of their own to the natural noise. That way it became possible to distinguish the desired signal from it getting drowned in noise.
There was a constant exchange of approach and attack of the problem between optical & radio segments of spectrum. But the techniques of receiving the energy differed in both. Such a huge body of engineering needed to refine their methds constantly to meet the demands of accuracies required by later generations of astronomers.
Radio methods revealed sources that were optically poor radiators. This is so because surface temperature of some stars belonging to spectral classes R, N & S and certain gaseous regions (Nubelae) are strong radio emitters. This follows Wien's law (for Blackbody radiation) that says wavelength of maximum radiation & temperature is
2.898 X 10^(-3)m K.
Now other windows in EMspectrum are also used like X rays for which sensors are required to be placed above the atmosphere ('Chandra').
b)Discuss the features of planet Mars gathered till date by the scientists.(5)
Ans:Mars is the fourth planet from the Sun in the Solar System. The planet is named after Mars, the Roman god of war. It is also referred to as the "Red Planet" because of its reddish appearance, due to iron oxide prevalent on its surface.
Mars is a terrestrial planet with a thin atmosphere, having surface features reminiscent both of the impact craters of the Moon and the volcanoes, valleys, deserts and polar ice caps of Earth. It is the site of Olympus Mons, the highest known mountain in the Solar System, and of Valles Marineris, the largest canyon. Furthermore, in June 2008 three articles published in Nature presented evidence of an enormous impact crater in Mars's northern hemisphere, 10,600 km long by 8,500 km wide, or roughly four times larger than the largest impact crater yet discovered, the South Pole-Aitken basin. In addition to its geographical features, Mars’ rotational period and seasonal cycles are likewise similar to those of Earth.
Physical characteristics:
Mars has approximately half the radius of Earth. It is less dense than Earth, having about 15% of Earth's volume and 11% of the mass. Its surface area is only slightly less than the total area of Earth's dry land. While Mars is larger and more massive than Mercury, Mercury has a higher density. This results in a slightly stronger gravitational force at Mercury's surface. Mars is also roughly intermediate in size, mass, and surface gravity between Earth and Earth's Moon (the Moon is about half the diameter of Mars, whereas Earth is twice; the Earth is about ten times more massive than Mars, and the Moon ten times less massive). The red-orange appearance of the Martian surface is caused by iron(III) oxide, more commonly known as hematite, or rust.
Geology:
Based on orbital observations and the examination of the Martian meteorite collection, the surface of Mars appears to be composed primarily of basalt. Some evidence suggests that a portion of the Martian surface is more silica-rich than typical basalt, and may be similar to andesitic rocks on Earth; however, these observations may also be explained by silica glass. Much of the surface is deeply covered by finely grained iron(III) oxide dust.
Hydrology:
Liquid water cannot exist on the surface of Mars with its present low atmospheric pressure, except at the lowest elevations for short periods[26][27] but water ice is in no short supply, with two polar ice caps made largely of ice.
Climate:
Of all the planets, Mars's seasons are the most Earth-like, due to the similar tilts of the two planets' rotational axes. However, the lengths of the Martian seasons are about twice those of Earth's, as Mars’ greater distance from the Sun leads to the Martian year being about two Earth years in length. Martian surface temperatures vary from lows of about −140 °C (−220 °F) during the polar winters to highs of up to 20 °C (68 °F) in summers.[26] The wide range in temperatures is due to the thin atmosphere which cannot store much solar heat, the low atmospheric pressure, and the low thermal inertia of Martian soil.
Rotation:
Mars’ average distance from the Sun is roughly 230 million km (1.5 AU) and its orbital period is 687 (Earth) days. The solar day (or sol) on Mars is only slightly longer than an Earth day: 24 hours, 39 minutes, and 35.244 seconds. A Martian year is equal to 1.8809 Earth years, or 1 year, 320 days, and 18.2 hours.
Q.5a) With the help of an example explain the systems view of life.(2)
Ans: A system is a set of some specific inter-related parts which are organized as one unit for some purpose. The parts work together and the entire combination forms one unit. A car producing company, which is organized to produce transport vehicles, can beviewed as a system too. For the effective functioning of the company, all of its parts, such as the department that purchases raw materials, the factory, the management and the sales department must work in unison. An animal or a plant is also made up of numerous parts which represent a well defined system. For example, in an animal body, the parts concerned with the in-take of food and digesting it, the bones arranged as a skeleton to support the body, the heart circulating blood to different parts of the body through the arteries and veins and the brain receiving signals and giving orders of various kinds together compose the system.
b)Explain the theory of natural selection proposed by Darwin.(3)
Ans:While Darwin’s theory of Evolution is a relatively young archetype, the evolutionary worldview itself is an old as antiquity. Ancient Greek philosophers such as Anaximander postulated the development of life from non-life and the evolutionary descent of man from animal. Charles Darwin simply brought something new to the old philosophy – a plausible mechanism called “natural selection”. Natural selection acts to preserve and accumulate minor advantageous genetic mutations. Suppose a member of a species developed a functional advantage (it grew wings and learned to fly). Its offspring would inherit that advantage and pass it on to their offspring. The inferior members of the same species would gradually die out, leaving only the superior members of the species. Natural selection is preservation of a functional advantage that enables a species to compete better in the wild. Natural selection is the naturalistic equivalent to domestic breeding. Over the centuries, human breeders have produced dramatic changes in domestic animal populations by selection individuals to breed. Breeders eliminate undesirable traits gradually over time. Similarly, natural selection eliminates inferior species gradually over time.
c)Explain the carbon cycle with the help of a diagram. In what way human activities have altered the balance of carbon cycle?(5)
Ans:
Human perturbations to the carbon cycle have been both direct and indirect. Obvious direct effects are the addition of new carbon to the active global carbon cycle through the combustion of fossil fuels, and the modification of the vegetation structure and distribution through land-use change. Deforestation, the removal of forest vegetation and replacement by other surface cover, has the largest land-use change impact on the carbon cycle, both through the loss of photosynthetic capacity in forest vegetation and the simultaneous release of large carbon stocks accumulated in forest ecosystems over long periods of time. Indirect human impacts on the carbon cycle include changes in other major global biogeochemical cycles, alteration of the atmospheric composition through the additions of pollutants as well as CO2, and changes in the biodiversity of landscapes and species.
Q.6a)List any four consequences of deforestation.(2)
Ans: Four consequences of deforestation:
1. Desertification, landslides, loss of biodiversity as a result of land fragmentation and loss of habitat.
2. If this wood is burned it will increase global warming (greenhouse effect)
3. Decrease of Carbon dioxide absorption which increases pollution and also contributes to the greenhouse effect.
4. Evapotranspiration (decrease of atmospheric moisture) water is simply
returned to the oceans instead of being recycled to downwind forests.
b)Explain the role of remote sensing method in resource exploration.(3)
Ans:Remote sensing is a method of collecting information about ground objects like soil, water, vegetation and minerals from a remote place such as an aircraft of a satellite. This technique not only enables us to locate various resources but also helps us to known about their quantity and quality. The method is used to collect information about an object, without physical contact with the object. The orbit of a sun-synchronous satellite is such that it always posses over a particular place on the earth at almost the same local time. It means whenever the satellite passes over a certain place on the earth, the position of the sun relative to that place is always the same. Thus the cameras of that satellite are enable to get photographs of that place always with nearly the same illumination every time it passes over that place.
c)Discuss the ways to manage water resources.(2)
Ans:The ways of managing water resources so as to provide water of right quality available for all kinds of uses are:
1. Need to check on excessive irrigation.
2. Sea water can be distilled by using solar energy, thus fresh water of good quality can be obtained.
3. Flood water can be delivered to areas where there is scarcity of water.
4. Recharging of groundwater is the most important aspect of the water management. The water sheds are covered with vegetation in the mountain and hills. It must be allowed in filtration of rain water, which finds its way to the aquifers.
5. By providing water filters.
d)Describe any three types of agrotechniques used in India.(3)
Ans:The three types of agrotechniques used in India are:
Cropping Systems
Since cultivable land is limited, the only way to meet our growing food needs is by growing two or more crops in a year from the same piece of land. Such multiple-cropping practices would generate more employment in rural areas and also fulfill our food needs. In a relay cropping system, a crop is sown before its preceding crop is harvested. The last irrigation given to a crop also serves as a pre-sowing irrigation to the next crop. This results in saving of water. In mixed cropping, compatible crops like chickpea and mustard are sown in parallel rows with wheat. Pigeonpea, mungbean, groundnut, soybean and cowpea can be grown in between rows of either sorghum, or maize, or sugarcane or cotton. Such intercropping systems have a high production potential and generate additional employment opportunities.
Input of Fertilisers
Nitrogen, phosphorus and potassium are the major nutrients that plants require. In addition, zinc, iron, manganese, boron, molybdenum and cobalt are also needed by plants in small quantities for healthy growth. Deficiency of any of these elements reduces yields, even when all other nutrients are available in adequate amounts. But, the excessive presence of some of these nutrients may prove toxic to plants.
Cereals require more nitrogen than phosphorus and potash. But pulses, whose m t nodules harbour bacteria, that fix nitrogen directly from the atmosphere, need adequate doses of phosphorus. As said earlier, the nutrient needs vary not only from crop to crop but also from soil to soil. It is essential, therefore, that the soil is tested and the required amounts of nutrients supplied according to the needs of the crops. Generalized application of commercially available fertilizer mixtures such as the one having nitrogen, phosphorus and potassium in the ratio of 120:60:40, is often quite wasteful and may even reduce yields. The time and depth of application of fertilizers is also very important. Research has shown that most farmers over-irrigate their crops when water is available. Consequently, not only is water, a precious input is wasted but the yields get depressed. Thus, crop management is as important as the crop variety in realizing optimum yields.
Crop Protection
Several kinds of insects, diseases, weeds, rodents and birds cause immense damage to crops both in the field and in storage. Pests have been there long before man came into existence. It is not possible to eliminate them entirely, either by developing varieties which resist attacks of pests or by using potent pesticides, for pests are adept in their struggle for existence and have always countered man's attempts to exterminate them. The best course for us is to resort to what is called "integrated pest management” that keeps the damage due to pests at the barest minimum. Integrated pest management will be effective if we grow resistant varieties in regions where incidence of pests is severe, ensure that crops grown one after another do not have common pests, instead of chemicals for pest control use biological organisms that attack the pest, apply pesticides only when the pest population has reached its threshold value, and take co-ordinated community action on pest control in adjoining fields over the whole village or block.
The war against pests is so long-drawn-out and difficult that farmers often use very high
I doses of pesticides at frequent intervals. This is a dangerous tendency. Excessive doses of pesticides leave harmful residues (also see Unit 16, Section 16.2) which find their way into the human body either directly from the consumed agricultural produce or through the milk of animals that feed on plants. It is essential, therefore, that pesticides are applied only in recommended doses that are harmless.
Q.7a)List any five groups of nutrients with one example food group of each. Write their roles in human health.(5)
Ans:Five types of nutrients are:
1 Carbohydrates (example potato)
2. Fat (example Ghee/oil)
3. Protein (example peas)
4. Minerals (example spices)
5. Vitamins (example tomato)
Roles of nutrients in human health:
We cannot live without food. Our hunger can be satisfied by any kind of meal, but to remain healthy and free of disease, our body requires certain kinds of food. The health of an individual is largely determined by the quality of food taken. Moreover, food makes a difference in our appearance, activity, behaviour, and in the quality of life.
Foods vary in their composition and no one type of food contains all we need, in the amounts that we need. A meal lacking in a particular requirement of our body for a prolonged period can result in disease, and even in death. Therefore, a knowledge of the food requirements of our body and various sources of obtaining them is essential. Studies carried out in many countries show that a good diet has promoted proper growth in children and has improved the general health of the people. A study of Japanese children has shown that an improved diet has increased the average height of children, from what it was a few decades ago.
A majority of the children of the developing countries of Asia, Africa and Latin America are generally poorly nourished. Some of them do not get enough to eat, while the diet of others is deficient in some foods that are essential for the body. So, we find a steady retardation in the physical and mental growth of these children and they suffer from various deficiency diseases.
The science of nutrition is a well developed discipline today. We know enough about what kind of nourishment is necessary for our child and adult population. The main problem is to make this information available to our people and to ensure that the food contains dl the necessary ingredients. Of course, the foods must be available to the people.
b)What are infectious diseases? Give the names of two diseases caused by viruses. How does our body battle against germs?(5)
Ans: Infectious Diseases:
An infectious disease is a clinically evident disease resulting from the presence of pathogenic microbial agents, including pathogenic viruses, pathogenic bacteria, fungi, protozoa, multicellular parasites, and aberrant proteins known as prions. These pathogens are able to cause disease in animals and/or plants. Infectious pathologies are usually qualified as contagious diseases (also called communicable diseases) due to their potential of transmission from one person or species to another. Transmission of an infectious disease may occur through one or more of diverse pathways including physical contact with infected individuals. These infecting agents may also be transmitted through liquids, food, body fluids, contaminated objects, airborne inhalation, or through vector-borne spread.
There are many diseases caused by viruses. Some are - chickenpox, measles and influenza.
Battle against germs:
When germs enters the body, it sends up a red flag causing certain cells in the body to wage war against the intruder. The first soldiers that are sent out are neutrophils or specialized white blood cells. They basically eat up the enemy.
But if these neutrophils aren'tsaturated with Vitamin C, they have a
difficult time maneuvering in the body and doing their job. If they are saturated with Vitamin C it increases their mobility and allows them to attack the intruding germs with more ease and at a greater speed.
Lymphocytes are another special kind of white blood cell important in the body's immune system and having plenty of Vitamin C also steps up their production levels adding more fighting power to the body's defense system.
But how do these soldiers know where to go to fight the enemy? The body produces a chemical distress signal, and much like a trained police dog tracks the scent of a bad guy, these neutrophils and lymphocytes follow the scent of the distress signal.
One thing that hinders their ability to do their job is that once they receive this distress signal, they may not receive it a second time if another attack is made on the body. They kind of become deactivated. The good news is, if the cells are saturated with Vitamin C, they are able to "hear" the second distress signal and will move on it. But cells that are Vitamin C deficient will not respond to a second call to action. This is often the reason that our bodies just don't fight off germs and invasions the way they should. Our little soldiers don't have the necessary equipment or ability to attack and win the battle.
Q.8a)Describe the structural components of central nervous system.(6)
Ans:Components of the Nervous System :
The nervous system is composed of both central (brain and spinal cord) and peripheral components, with the latter having both somatic and autonomic (parasympathetic and sympathetic) subdivisions.
When we consider the central nervous system, its major purpose is to receive, process/interpret, and send out information. To accomplish these goals, the brain itself is composed of inter-related but specialized areas of function that are carefully coordinated through a network of connections.
a.Brain. The brain fills the cranium and weighs about three pounds in the average adult. The brain is shaped like a mushroom. The brain consists of four principal parts: the brain stem, the diencephalon, the cerebrum, and the cerebellum. The diencephalon, also known as the forebrainstem, includes the thalamus and hypothalamus.
b.Spinal Cord. The spinal cord is a cylindrical structure which extends from the foramen magnum through the spinal foramina of the vertebral column to the upper portion of the lumbar region. Extension varies from the 12th thoracic vertebra to the 2nd lumbar vertebra. The length of the cord remains fairly constant in adults: 18 inches in males and 16 inches in females. The conus medullaris is the cone-shaped termination of the cord. This portion of the spinal cord weighs about one ounce and is approximately one and one-half inches wide. The spinal cord itself appears wider from right to left than from anterior to posterior. The size and shape, however, do vary depending on the vertebral region. For example, the spinal cord presents cervical and lumbar enlargements, which are areas of nerve origin in the upper and lower lumbar region. The spinal cord is composed of a series of 31 segments. A pair of spinal nerves comes out of each segment. The region of the spinal cord from which a pair of spinal nerves originates is called the spinal segment. Both motor and sensory nerves are located in the spinal cord.
c. Meninges. The meninges are the three membranes that envelop the brain and the spinal cord. The outermost layer is the dura mater. The middle layer is the arachnoid, and the innermost layer is the pia mater. These three spinal meninges cover the spinal nerves to the point where the spinal column goes through the intervertebral foramen. The meninges offer protection to the brain and the spinal cord by acting as a barrier against bacteria.
d. Cerebrospinal Fluid (CSF). The cerebrospinal fluid protects the brain against injury. CSF circulates through the subarachnoid space (the area between the arachnoid and pia mater), around the brain and spinal cord and through the ventricles of the brain. In addition to protecting the brain, this clear fluid nourishes the central nervous system and carries off wastes.
b)Do you think the methodology of reward and punishment helps in learning process? Justify your answer.(4)
Ans:
Among different kinds of learning forms, one form of learning comes about through reward and punishment. For example, if you have a pet puppy and you want to train it to ‘sit down’, he would not understand the words ‘sit down’ as he doesn’t understand English. But if, while giving the command, you physically make him sit down and give him a biscuit, then on the experience being repeated a few times, the puppy will learn to obey the command. The puppy will associate the sound of the command to sit with the reward of a biscuit. After training, the puppy will sit down as soon as he is given the command – ‘sit’ even if he is not given any reward. In some situations, punishment would also lead to the same result. We learn a lot of things by such processes. For example, when a baby is hungry it may cry which attracts the attention of the mother and may result in his being fed some milk. The child will soon learn the trick. Similarly, a student in the math’s class solves a problem correctly. He receives the praise of his teacher. The next time he will approach other math’s problem with greater zeal so as to get the teacher’s approval. All of us are familiar with situations where punishment is used to reduce undesirable behavior. Spanking, reprimands or holding back privileges are common means. For example, the traffic police impose fines on motorists if they cross a red light or parents do not allow their children to watch television if the home work is not done. This principle of reward and punishment is used in the educational field widely performance or good actions and discouraging or punishing poor performance, or activities. The same principle is used in society and public organizations. Bonus for productivity in a factory, or cut in wages if there is low production, are examples or the same kind.
Q.9a)Discuss the role of any one mass communication medium in promoting education.(5)
Ans:Mass communication is the term used to describe the academic study of the various means by which individuals and entities relay information through mass media to large segments of the population at the same time. It is usually understood to relate to newspaper and magazine publishing, radio, television and film, as these are used both for disseminating news and for advertising.
Many studies have proven that the Internet is one of the most powerful sources of information in the world wide for all races and cultures. Some schools nowa days have eliminated the books and the note books and changed them with laptops and emails. An increasing number of young generations prefer this modern technology over the old ways in studying. Internet can be helpful indeed to both students and teachers in many ways and this is why!!!
First of all, the Students find the Internet a saving time invention. While it takes hours for one to search the library for the information, it takes only an Enter click to find what he is seeking for. Also, it is more fun and interesting to dig in the internet than in books because web sites are usually filled with colors and designs while the books are plain and some are even old.
Another example of Internet's importance in education is the teachers. They can use this giant source in teaching students who are distant, they can up load their courses on the webs so the whole world benefits from it , Also, Internet can be a lie detective for teachers to use and see if their students were cheating !! Internet expands teachers time, instead of correcting in a limited or no time they have all day long by receiving the home works and sending them back to the students to correct their mistakes .
Internet for sure is an affective weapon in education; however we can not replace it or make it a superior to the importance of the book.
b)What is the importance of research and development in the industry? What technological developments have taken place in energy sector till date?(5)
Ans: A developing country like ours aims to reduce its technological dependence on other countries. We shall be able to achieve this by increasing our R & D efforts. Products and processes developed in our own country will be based on local raw materials and will take into consideration other local factors such as weather. In the process, we will also have the requisite manpower for maintenance as well as further improvement of technology. We should match our R & D efforts with the objectives and policies of our country. Apart from the government laboratories, private industry should take more and more active part in research activities. The commercial application of scientific discoveries can be carried out more easily if there is a direct link between the laboratory and industry. In other words it would be better if industrial units have an R & D set up within themselves.
Our indigenous R & D units should try to reduce the threat to our environment through innovations in industrial processes. Pollution of environment by industries is a very serious menace in the developed countries. As you know most of our big industries were set up before the oil prices sky-rocketed in 1973. As a result they rely heavily on oil as their source of energy. With the unprecedented rise in oil prices, and also taking into consideration the limited world reserves of oil. We should try and look for alternative source of energy which will increase our profitability in the long run. Some experiments are being done with solar energy, and it has also been put to use in some places. But we haven't yet tapped its full potential.
It may be noted that the concept of modernization is integrally related to the Improvement of processes and products. But modernization as mere gimmickry. for example, to introduce computers where one can do without them, or installing remote control communication systems and the like can only increase overheads and lead to handicaps in trade. A balanced approach to modernization seems to be the need of the hour, and we need to strengthen our own R & D efforts for this.
Q.10Write the applications of the following:(2½´4)
a)Fibre optics
Ans:A technology that uses glass (or plastic) threads (fibers) to transmit data. A fiber optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves.
Fiber optics has several advantages over traditional metal communications lines:
1. Fiber optic cables have a much greater bandwidth than metal cables. This means that they can carry more data.
2. Fiber optic cables are less susceptible than metal cables to interference.
3. Fiber optic cables are much thinner and lighter than metal wires.
3. Data can be transmitted digitally (the natural form for computer data) rather than analogically.
The main disadvantage of fiber optics is that the cables are expensive to install. In addition, they are more fragile than wire and are difficult to splice.
Fiber optics is a particularly popular technology for local-area networks. In addition, telephone companies are steadily replacing traditional telephone lines with fiber optic cables. In the future, almost all communications will employ fiber optics.
b)Biotechnology
Ans:Biotechnology is perhaps, best defined as the industrial utilization of biological systems or processes. The ability to control and manipulate microbes and use them for various applications has resulted in the current biotechnology. The two main techniques in biotechnology are:
vGenetic engineering and
vEnzyme immobilization
The most ancient biotechnological art is fermentation. Living micro-organisms have been used for centuries to make curds, condiments, cheese and vinegar, to prepare dough for bread and to brew alcohol. But today biotechnology provides much more simple processes with the help of powerful microscopes and carefully done experiments in the laboratory, we have came to understand that the thing microbes involved in these processes are small biochemical factories. And they can be used for a variety of purposes, related to health, medicine, food, pollution control etc.
c)Nuclear fission
Ans:When a nucleus fissions, it splits into several smaller fragments. These fragments, or fission products, are about equal to half the original mass. Two or three neutrons are also emitted.
Nuclear Fission
The sum of the masses of these fragments is less than the original mass. This 'missing' mass (about 0.1 percent of the original mass) has been converted into energy according to Einstein's equation.
Fission can occur when a nucleus of a heavy atom captures a neutron, or it can happen spontaneously.
A chain reaction refers to a process in which neutrons released in fission produce an additional fission in at least one further nucleus. This nucleus in turn produces neutrons, and the process repeats. The process may be controlled (nuclear power) or uncontrolled (nuclear weapons).
If each neutron releases two more neutrons, then the number of fissions doubles each generation. In that case, in 10 generations there are 1,024 fissions and in 80 generations about 6 x 1023 (a mole) fissions.
c)Robotics:
Ans: Robotics can be described as the current pinnacle of technical development. Robotics is a confluence science using the continuing advancements of mechanical engineering, material science, sensor fabrication, manufacturing techniques, and advanced algorithms. The study and practice of robotics will expose a dabbler or professional to hundreds of different avenues of study. For some, the romanticism of robotics brings forth an almost magical curiosity of the world leading to creation of amazing machines. A journey of a lifetime awaits in robotics.
Robotics can be defined as the science or study of the technology primarily associated with the design, fabrication, theory, and application of robots. While other fields contribute the mathematics, the techniques, and the components, robotics creates the magical end product. The practical applications of robots drive development of robotics and drive advancements in other sciences in turn. Crafters and researchers in robotics study more than just robotics.
The promise of robotics is easy to describe but hard for the mind to grasp. Robots hold the promise of moving and transforming materials with the same elan and ease as a computer program transforms data. Today, robots mine minerals, assemble semi-processed materials into automobile components, and assemble those components into automobiles. On the immediate horizon are self-driving cars, robotics to handle household chores, and assemble specialized machines on demand. It is not unreasonable to imagine robots that are given some task, such as reclaim desert into photovoltaic cells and arable land, and left to make their own way. Then the promise of robotics exceeds the minds grasp.
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