PSEB Class 8 Computer Science Chapter 8 Memory Units Solution

PSEB Punjab Board Class 8 Computer Science Textbook Solution Chapter 8 Memory Units Exercise Questions and Answers

 

2. Write Full Forms for the following terms :-

1) MB : Mega Bytes
2) GB : Giga Bytes
3) SRAM : Static Random Access Memory
4) PROM : Programmable Read Only Memory
5) IR : Instruction Registers

3. Short Answer Type Questions :-

1) What is Memory ?
Ans :- Memory is the space which is used to store data and instructions, for immediate
desired results.

2) Write the names of different types of Memories.
Ans :- There are two different type of Memories which are i) Internal ii) External
memories
i) Internal Memory :- CPU Registers, Cache Memory, Main Memory
ii) External Memory :- Magnetic Disk, Optical Disk, Magnetic Tape.

3) What is Primary Memory ?
Ans :- Primary Memory/Main Memory is the memory, which stores the data/ information
is for a temporary basis. Hence it is also called as volatile memory.

4) Write the names of various types of ROM.
Ans :- The names of the various types of ROM are PROM (Programmable Read Only
Memory), EPROM (Erasable and Programmable Read Only Memory), EEPROM (Electrically Erasable and Programmable Read Only Memory), MROM (Masked Read Only Memory).

4. Long Answer Type Questions :-

1) Explain RAM and ROM ?
Ans :- i) RAM :- RAM stands for Random Access Memory. The instructions or data
stored on the RAM is retained/holds only for a temporary/short period of time till there is
continuous supply of power. In the modern computers, RAM is always treated as Main Memory or Primary memory, where as CD, DVD, Hard disk, floppy disks will be treated as Secondary auxiliary devices. RAM also supports reading and writing operations. Data and Instructions can be stored when the RAM is been operated/ in used.
There are mainly two types of RAM which are Static and Dynamic which are as follows:-

a) Static RAM:- It is popularly known as SRAM which does not needs to be refreshed
thousands of times per second, which as result makes it more faster and much
costlier as compared to Dynamic.

b) Dynamic RAM :- Dynamic RAM needs to be refreshed thousand of times per
second. Dynamic RAM is slow and much cheaper than SRAM. Both of these RAMs are volatile in nature

ii) ROM :- ROM stands for Read Only Memory which means the data or instructions
stored on ROM remains for a longer period of time. The programs written on ROM cannot be changed. ROM is a memory to store the instructions related to boot programs (programs that start up the system), printer driver files and fonts.
The different types of ROM are as followed :-

a) PROM:- It stands for Programmable Read Only Memory. They are manufactured as
blank chips, which are used to write any data with the help of PROM programmer.

b) EPROM:- This is a type of memory which can erase the contents/data written on the
PROM by exposing it to the ultraviolet light. EPROM stands for Erasable Programmable Read Only Memory.

c) EEPROM:- Instead of using ultraviolet light, this memory uses an electricity to erase
the contents/programs stored on PROM. EEPROM abbreviation is Electricity Erasable
Programmable Read Only Memory.

2) Explain the External Memory
Ans :- Secondary memory is also known as Auxiliary memory or External memory.
The data and instructions stored on the secondary memory is stored for a longer period/
permanently. As compared to primary memory the secondary memory is much cheaper and slower. The data and instructions stored on secondary memory is not directly accessed by the processor but it requires I/O channels. Secondary memory has higher storage capacity. The data/instructions stored on the secondary memory remains unchanged, even if the power is turned off. Hence it is Non-volatile memory. The examples of secondary storage devices are:-
Hard disk, CD(Compact Disk), DVD(Digital Versatile Disk), pendrives,.

3) Explain the Characteristic of Secondary Memory
Ans :- The characteristics of Secondary Memory are as follows :-
i) Can be reused again and again :- The data/information stored on secondary devices/memory can be retained/holded for a long period of time and hence can be
accessed/made used of/ utilized any number of times as per the requirement i.e
means you can access the data again and again whenever it is needed. There no
limitation to access the data.

ii) Non – volatile memory :- The data/information stored on secondary memory are
stored is not for temporary, its permanently which means the contents or data does
not gets lost even if there is power failure or when computer is been switched off.

iii) Safety :- The data/information stored in secondary memory are highly secured in
terms of safety, as if only the authorized person will be able to access the
data/information.

iv) Convenience :- The data/information stored in secondary memory can only be
utilized/made used by the person to whom we have given the authority/permission.

v) Storage Capacity :- In the secondary memory, if the data/information that we want to store on a disk is more/huge, then we can store it into many disks as much
required.

vi) Cost :- In Secondary memory, the data/information is stored on tapes or disks, hence it is less expensive in comparison to primary memory.

vii) Slow in speed :- The data/information stored on Secondary memory is slow in speed in comparison to Primary memory.

4) What are Tracks and Sectors ?
Ans :- a) Tracks :- Tracks are the circles that you see on the surface of the disk. These circles are numbered beginning from zero from the outermost/part of the circle to innermost/part of the circle. As per the capacity of the disk, the various tracks on the disks differs.

b) Sectors :- The intersection/breaking of tracks in smaller parts is to be termed as
Sectors. There are 8 sectors mend for each tracks. Sectors holds the memory capacity of  512 bytes. Following is the to calculate the storage capacity of a disk Number of sectors per track x Number of bytes per sector

5) What is Cache Memory? What are its advantages and disadvantages?
Ans :- Cache is the special small and high speed storage/memory within the central processing unit of the computer system for frequent access. It deals with the increase in the processors speed. When the processor performs the task of read and write operations it first checks cache memory. The advantages and disadvantages of Cache memory are as followed

Advantages

i) In comparison to main memory, cache memory is much faster.
ii) As cache memory processing is very fast, it takes less time to get accessed as compared in terms of Main memory.
iii) As it takes very less time to get accessed and is much faster in speed, it stores only those programs can be executed very quickly/in a very short period of time.
iv) The data/information stored on cache memory is for temporary use. It is volatile in nature.

Disadvantages

i) The data/information that is stored in the cache memory is stored at a limited stage i.e. means its has very limited storage capacity. You cannot store bulky data/information on cache memory.
ii) As compared to other memories its very expensive.
iii) The data/information stored on cache memory cannot be retrieved back later on as per the need/requirement. As it is stored temporary.
iv) It does not accept all types of programs. Its much hectic/fed up to search out/look out for the program which executes in very short time.

 

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Updated: July 1, 2021 — 4:46 pm

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  1. Is very good com

    1. Very nice please add text book in it for more help of student

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