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CBSE · Class 11 · Computer Science

Computer System

Standard difficulty · 20 questions · 40 marks · Time: 36 minutes

Name: Date: Score: ____ / 40

Show your working for Sections B and C. Answers are on the last page — try every question first!

Section A — Choose the correct answer8 × 1 = 8 marks
1.
Which part of the CPU carries out arithmetic and logical operations?
  1. the cache memory
  2. the address bus
  3. the control unit
  4. the ALU (arithmetic logic unit)
2.
How many bytes are there in 52 MB?
  1. 54,525,952
  2. 52,000,000
  3. 53,248,000
  4. 53,248
3.
Which of these is an input device?
  1. monitor
  2. speaker
  3. printer
  4. fingerprint scanner
4.
What is raw facts that have not yet been processed called?
  1. data
  2. ROM
  3. assembler
  4. cache memory
5.
Which of these is the fastest to read data from?
  1. a solid state drive
  2. an optical disc (DVD)
  3. registers
  4. RAM
6.
How many photos of 15 MB each can be stored, at most, on a 2 GB memory card?
  1. 136
  2. 138
  3. 133
  4. 137
7.
How many nibbles are there in 14 bytes?
  1. 28
  2. 56
  3. 112
  4. 14
8.
A 32-bit data bus moves 32 bits in one transfer. How many bytes does it move in 9 transfers?
  1. 36
  2. 288
  3. 72
  4. 40
Section B — Short answer8 × 2 = 16 marks
9.
Name the three main parts of a computer system and say what each does.
10.
Convert 75,776 TB into PB.
11.
Convert (a) 9 GB into MB (b) 18,432 KB into MB.
12.
Name the term for each: (a) the part of the CPU that does calculations and comparisons (b) a translator that converts a whole program into machine code before it runs
13.
Is each an input or an output device? (a) touchpad (b) monitor
14.
Is each memory volatile or non-volatile? (a) an optical disc (b) cache memory
15.
An 8 GB music player is empty. Songs are 7 MB each. (a) How many whole songs fit? (b) How many MB are left over?
16.
Is each system software, application software or a language translator? (a) an antivirus utility (b) a spreadsheet program
Section C — Word problems4 × 4 = 16 marks
17.
Draw and explain the block diagram of a computer system.
18.
A 16 GB pen drive holds 336 photos of 5 MB each and 11 videos of 661 MB each. (a) How many MB are used? (b) How many MB are free? (c) How many more photos of 5 MB can it take?
19.
A pen drive copies data at 50 MB per second. (a) How many seconds does a 3,350 MB file take? (b) How many such files can be copied completely in 8 minutes? (c) How many MB are copied in 8 minutes?
20.
A computer has a 32-bit data bus and a 18-bit address bus, and each memory location holds 1 byte. (a) How many bytes move in one transfer on the data bus? (b) How many locations can be addressed? (c) What is the largest memory it can use, in KB?
AmbifulWorksheets
Practice that never repeats
CBSE · Class 11 · Computer Science

Answer key

Computer System · AW-11CS-CSY-2026-V1 · For parents — fold back or tear off before handing the sheet to your child.

QAnswerWorking
1(d) the ALU (arithmetic logic unit)—
2(a) 54,525,95252 × 1024 × 1024
3(d) fingerprint scanner—
4(a) data—
5(c) registersregisters, cache, RAM, SSD, hard disk, optical disc: fastest to slowest
6(a) 1362 × 1024 = 2,048 MB; 2,048 ÷ 15 = 136 (whole photos only)
7(a) 28a byte is 8 bits = 2 nibbles
8(a) 3632 ÷ 8 = 4 bytes each, × 9
9Input devices take in data, the CPU processes it, and output devices give out the results; memory stores the data and programs.—
1074 PB75,776 ÷ 1024
11(a) 9,216 MB; (b) 18 MB9 × 1024; 18,432 ÷ 1024
12(a) ALU; (b) compiler—
13(a) input (b) output—
14(a) non-volatile (b) volatilevolatile memory loses its contents when the power goes off
15(a) 1170; (b) 2 MB8,192 MB = 7 × 1170 + 2
16(a) system software (b) application software—
17Input unit → CPU (ALU, control unit, registers) → output unit, with primary memory connected to the CPU and secondary storage below; arrows show data and control flow.—
18(a) 8,951 MB; (b) 7,433 MB; (c) 1,486336 × 5 + 11 × 661 = 8,951; 16,384 − 8,951 = 7,433; 7,433 ÷ 5
19(a) 67; (b) 7; (c) 24,000 MB3,350 ÷ 50 = 67 s; 480 ÷ 67; 50 × 480
20(a) 4; (b) 262,144; (c) 256 KB32 ÷ 8; 2 to the power 18; 262,144 bytes ÷ 1024