Grade V, Chapter 2

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Learn with Hafiza Palwasha


OXFORD (Book 5), KEYBOARD
Computer Science With Application Software (Third Edition).

Solution

Chapter No. 2
Data Devices 

NEW WORDS
Students should extract new words by themselves from chapter No. 1 and write them on neat copies as vocabulary words. There is no need to memorize these words but students should be able to read and understand these words as I explained and discussed in class.

NEW TERMS AND ABBREVIATIONS
Students should learn these terms and abbreviation. It will be the part of exam.
1.    Bit:
       It is the smallest unit use to measure the computer memory. It is either 1 or 0.
2.    Byte:
       It is the unit to measure the computer memory. When 8 bits combines, it forms one byte.
3.    VDU:
       It stands for Visual Display Unit. It is output device which gives better view on screen because of it's wide diagonal length.
4.    CD:
       CD stands for Compact Disc. It is a memory device.
5.    Volatile memory:
       Volatile memory is the memory in which we lost our data when power is switched off.
6.    RAM:
       RAM stands for Random Access Memory.
7.    ROM:
       ROM stands for Read Only Memory.
8.    PROM:
       PROM stands for Programmable Read Only Memory. It is type of ROM whose information cannot be changed.
9.    EPROM:
       EPROM stands for Erasable Programmable Read Only Memory. It is type of ROM whose information can be erased by using ultraviolet light.
10.  EEPROM:
       EEPROM stands for Electrically Erasable Programmable Read Only Memory. It is type of ROM whose information can be erased by using electrical signals.
11.  CD-ROM:
       CD stands for Compact Disc and ROM stands for Read Only Memory.
12.  DVD:
       DVD stands for Digital Versatile Disc or Digital Video Disc.
13.  USB:
       USB stands for Universal Serial Bus. It is very small storage device and easy to use.

Exercise
Solution

Page No. 22
Objective Type Questions
Q No. 1: Choose the correct option.
Solution:
a.   A __________ is similar to a TV screen.
       i. VDU (is correct)
b.   A printed output is called the __________.
       ii. Hard copy (is correct)
c.   The devices through which data and instructions are entered into a computer are called __________.
       i. Input devices (is correct)
d.   Touch screens are used in a/an:
       iii. both i. and ii (is correct)
e.   __________ is the result or the output given by a computer.
       i. Information (is correct)

Page No. 22 & 23
Descriptive Type Questions
Q No. 1: Answer the following.
a. Which type of memory is known as non-volatile memory?
Answer: Secondary memory is known as non-volatile memory.

b. Arrange in ascending order the following units of memory:
TB          GB          KB          MB
Answer: The ascending order will be as follows:
1. KB
2. MB
3. GB
4. TB

c. How does a touchscreen differ from a graphics tablet? Which do you think is the most useful mechanism? Why?
Answer: In touchscreen we interact and gives input to the computer by touching through finger tip while in graphic tablet we use special pen called stylus to interact and gives input to the computer.
* I think touchscreen is most useful mechanism because the interaction is easy with computer and we don't need any extra tool.

d. If a shopkeeper needs to print out numerous receipts for his shop, what kind of printer could he/she use? Do you think it is always important to print out receipts? Does this raise an environmental issue?
Answer: In this case very high quality printing is not required so dot matrix printers should be preferable in this case.
It is not always important to print out receipts because we can use emails or mobile numbers to send receipts. It will decrease cost and because of less usage of paper will not raise an environmental issue.

e. Does the computer lose all the data when it is switched off? Explain your answer.
Answer: Computer not always loose the data when it is switched off because it depends on which memory it is saved.
1. If it is saved in volatile memory then we loose the data when it is switched off.
2. If it is saved in non-volatile memory then we do not loose the data when it is switched off.

f. Which storage device would you prefer to use to save your homework files? Why do you think this.
Answer: I will prefer USB because it's secondary memory device which is portable, handy and pocket size. So, I can easily use it to present my saved homework.

Additional Questions
Q: Write the higher memory units of transferring data.
Answer: Following are the higher memory units of transferring data:
1. 1 KB = Kilobyte:
    2^10 B
    = 1024 B
2. 1 MB = Megabyte:
    2^10 KB
    = 1024 KB
    = 1024 * 1024 B
3. 1 GB = Gigabyte:
    2^10 MB
    = 1024 MB
    = 1024 * 1024 * 1024 B
4. 1 TB = Terabyte:
    2^10 GB
    = 1024 GB
    = 1024 * 1024 * 1024 * 1024 B
5. 1 PB = Petabyte:
    2^10 TB
    = 1024 TB
    = 1024 * 1024 * 1024 * 1024 * 1024 B

Q: Draw the flow chart of computer memory.
Answer: 

Q: What is the difference between RAM and ROM.
Answer: RAM is a volatile memory which means it is temporary memory and the data is lost when computer is switched off.
ROM is non-volatile memory which means it is permanent memory and the data will save permanently even when computer is switched off.

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