RBSE Solutions for Class 7 Science Chapter 13 Computer
RBSE Solutions for Class 7 Science Chapter 13 Computer
Rajasthan Board RBSE Class 7 Science Chapter 13 Computer
Text book Exercise
Question 1.
Which device is not an output device.
(a) Monitor
(b) Printer
(c) Key board
(d) Plotter
Answer:
(c) Key board
Question 2.
The part of central processing unit is:
(a) Memory
(b) A.L.U
(c) Control Unit
(d) All of the above
Answer:
(d) All of the above
Question 3.
Input device is :
(a) Keyboard
(b) Mouse
(c) Scanner
(d) All of the above
Answer:
(d) All of the above
Fill in the blanks :
1. All the actions of computer are controlled by …………….unit.
2. To check the examination answer books, …………device is used.
3. Monitor, printer, speaker and plotter are…………..device.
4 …………………printer speed is measured in CPS.
Answer:
- Central processing
- Optical mark
- output
- Dot matrix
Short Answer Type Questions
Question 1.
Write names of input devices.
Answer:
- Keyboard
- Mouse
- Magnetic ink character recognition
- Optical character recognition
- Optical mark reading
- scanner
- Touch screen
- Microphone
- Web camera.
Question 2.
What is the difference between CRT and LCD monitor?
Answer:
CRT- This monitor has cathode ray tube.This monitor is bigger in size and takes more space on the table, they are heavy and more electricity is consumed by its use. Therefore today, they are used less.
LCD- Liquid Crystal Display is used in this monitor. Since they are thin, they take less space on the table, they are lighter and consume less electricity when used.
Question 3.
If you want to purchase a printer which one will be your choice and why?
Answer:
We will buy a laser printer, because it prints high quality matter. It prints paper very fast. Print outs taken from this printer is of high quality.
Question 4.
Define computer on the basis of their functions.
Answer:
Computer is a device which converts data into useful information. Computer takes data in a form of a input. Stores data and work on it as per our requirement. To write, process it and print it in a desired format.
Long Answer Type Questions
Question 1.
What are the characteristics of computer. Explain the same.
Answer:
Computer has the following characteristics.
- Storage Capacity : Computer has extraordinary capacity to store data. It is measured in bytes. It can store any type of data.
- Accuracy : Computer never makes any error because it works on the principle that as the input so will be the output. If input is wrong then output will also be wrong.
- Speed : Computer can do complicated calculations in a very short time.
- Automation : Computer is an automatic machine which when once started, works according to direction as per the given programmer.
- Diligence : Computer is an electronic device which can do restless work for long time without any exhaustion.
- Widespread Utility : The use of computer is increasing day by day. Its utility is increasing in every aspect of life like banking, in education, train operation, printing etc.
Question 2.
Into how many parts key board keys can be divided?
Answer:
Keys of the keyboard can be divided into 3 parts.
(1) Alphanumeric keys- In this part of keys, we have alphabets (A-Z), Numeric keys, character (0-9) and special characters like space bar, <,>,’,*,#,@,$,%,A,&,(,),/,?,[,], {,} and special keys are there like Shift, Enter, Back¬space,Tab,Ctrl.Esc&Alt.
(2) Numeric keys- This part has keys where there are numericals from 0-9 and other keys are there like-Num lock/,*,-,Home,Page Up, Page Down,Insert and Enter keys.
(3) Function keys- On the upward side of the
keyboard there are 12 keys, named as F1,F2,F3,F4,F5,F6,F7,F8,F9,F10,F11,F12. They all have different functions.
Other Important Questions
Multiple Choice Questions
Question 1.
Which is not related to Central Processing Unit
(a) Memory
(b) A.L.U
(c) Control Unit
(d) Scanner
Answer:
(d) Scanner
Question 2.
What is used to print big pictures or maps on paper.
(a) Plotter
(b) Dot Matrix Printer
(c) Laser Printer
(d) Ink Jet Printer
Answer:
(a) Plotter
Question 3.
Speed of which is measured in DPI?
(a) Laser Printer
(b) Ink Jet printer
(c) Dot Matrix Printer
(d) Plotter
Answer:
(a) Laser Printer
Question 4.
Which of the following is not a quality of computer?
(a) Storage
(b) Accuracy
(c) Automation
(d) Inactivity
Answer:
(d) Inactivity
Question 5.
Which of the below is a composition written by Smt. Shakuntala Devi
(a) Son with numbers
(b) Astrology for u
(c) Puzzles to puzzles
(d) All of these
Answer:
(d) All of these
Fill in the blanks
1. Unit of computer is used to get useful ……………….. from the data feeded in it.
2. With the help of……………. , majority of data and instructions are given to the computer.
3. With the help of…………….. , cheques are checked in banks.
4. With the help of……………. , bills are made in large quantities.
Answer:
- Information
- Key board
- MICR
- OCR
Very Short Answer Type Questions
Question 1.
Define a computer.
Answer:
Computer is a device, which converts data into meaningful information.
Question 2.
Name the parts of computer.
Answer:
- Input Unit
- Central Processing Unit
- Output Unit.
Question 3.
What is the function of A.L.U?
Answer:
By A.L.U. (Arithmetic and Logical unit), addition, subtraction, multiplication and division are done.
Question 4.
What are input devices?
Answer:
The input devices are used to put data into the computers.
Question 5.
What is the function of scanner?
Answer:
It is used to store documents or pictures available on any paper into the digital memory of computers. Its working principle is almost similar to xerox machine. It can provide duplicate copy of any document.
Question 6.
What is the function of touch screen?
Answer:
It is alternate of key board. Monitor screen is used to give instructions to computers by touching the exact position on screen.
Question 7.
What is microphone?
Answer:
It is an input device to feed voice as inputs.
Question 8.
Write the names of output devices generally used.
Answer:
Monitor, Printer, Speaker, etc.
Question 9.
How many types of monitors are there?
Answer:
Mainly there are three types of monitors:
- CRT monitor
- LCD monitor
- LED monitor
Question 10.
How is speed of lesser printer measured?
Answer:
It is measured in DPI Dots per Inch.
Short Answer Types Questions:
Question 1.
What is CPU? How many parts of CPU are there?
Answer:
It is the main part of a computer. It stores data, performs different types of calculations and controls all the actions of computers. It has three parts:
- Memory
- A.L.U (Arithmetic and Logical unit)
- Control unit
Question 2.
Write the functions of different parts of Central Processing Unit.
Answer:
- Memory : Memory is that part of computer which stores different types of data and instructions.
- A.L.U : Its main function is to perform logical and comparative calculations – addition, subtraction, multiplication, division, etc.
- Control unit : It controls all the processes of computers.
Question 3.
What is OCR (Optical character recognition)?
Answer:
It is used for very high speed reading (approx. 300 pages per hour) of printed, typed or handwritten letters with optical or LASER scanner. This technique is mostly used in those institutions where large number of bills are made.
Question 4.
What is OMR?
Answer:
It is a device which is used to check the presence or absence of pen or pencil mark on a paper. In this context, light is thrown on the marked paper and reflected light is checked. This technique checks only boxes at specific places and boxes filled with pencil on printed cards or forms. OMR is highly essential device to check the answer books of an exam.
Question 5.
What is a scanner? Explain its working.
Answer:
It is used to store documents or pictures available on any paper into the digital memory of computers. Its working principle is almost similar to xerox machine. It can provide duplicate copy of any document.
Question 6.
What is a microphone or a web camera?
Answer:
Microphones : It is an input device to feed voice as inputs. .
Web Camera : The activity of a person we are conversing with who is in another city or abroad can be viewed on computer screen by web cameras.
Question 7.
What is a monitor? How many types of monitors are there?
Answer:
Monitor or V.D.U is the main out put device. Mainly there are three types of monitors:
- CRT monitor
- LCD monitor
- LED monitor
Question 8.
LED monitors are most commonly used now a days, Why?
Answer:
In view of its good quality and low electrical consumption this monitor is most preferred choice
Light emitting diode is placed in this monitor.
Long Answer Type Questions:
Question 1.
What is a mouse? What is its function?
Answer:
It is one of the most popularly used input device. Movement of the ball on the surface moves the cursor on the screen. When cursor reaches the desired position then by click of the mouse button on cursor we can choose the instructions that is to be processed. At present optical mouse that lack a ball are more commonly used.
Question 2.
What is MICR (Magnetic Ink Character Recognition)?
Answer:
MICR technology is used mainly in banking sector where cheques are checked in abundance. In this technique, script is made to emerge by the use of special characters that come out of a special typewriter that has magnetic material mixed in it. It is used to check the factuality of records.
Question 3.
What is a printer? Explain any two commonly used printers.
Answer:
It is that out put device by which a hard copy is taken in printed form. The commonly used printers are:
(a) LASER Printer
(b) Ink Jet printer.
(c) Dot matrix printer
(d) Line printer
(a) Laser Printer : High quality printing work is done by LASER printer. It prints paper with speed. Speed of printing is measured in DPI (dots per inch).
(b) Ink Jet Printers : It prints images by spraying the ink on paper. However, the quality of image is low as compared to that of LASER printer. Its printing speed is also lower than LASER printer.
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