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MCQs — Computer Systems

Practice questions for Computer Science.

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Question 121

The control unit is interpreting an instruction to find out which operation is required. Which stage is this?

A. Fetch

B. Execute

C. Decode

D. Store

Question 122

How does data travel between the CPU and RAM inside a computer?

A. As printed pages

B. As sound waves through speakers

C. As electrical signals along buses

D. As letters carried by hand

Question 123

Inside a computer, data is stored and moved in the form of:

A. Photographs

B. Words of the English language

C. Musical notes

D. Binary digits (bits)

Question 124

A student types the letter 'A' on the keyboard and it appears on the screen. Which path shows how the data moves?

A. Keyboard ? CPU/memory ? monitor

B. Monitor ? CPU ? keyboard

C. Keyboard ? printer ? monitor

D. Monitor ? keyboard ? hard disk

Question 125

Which of the following is an example of internal data movement rather than communication with another computer?

A. Sending an email to a friend

B. The CPU fetching an instruction from RAM

C. Downloading a file from a website

D. Sharing a printer over a network

Question 126

Before the CPU can read a value from memory, it must first specify:

A. The colour of the monitor

B. The name of the printer

C. The address of the memory location

D. The size of the keyboard

Question 127

Why does the CPU communicate with memory so frequently?

A. To display pictures

B. To connect to the internet

C. To charge the battery

D. To fetch instructions and to read and write data

Question 128

The CPU has finished a calculation and wants to keep the result in memory. Which operation does it perform?

A. A write operation

B. A read operation

C. A print operation

D. A scan operation

Question 129

The CPU needs the instruction stored at memory location 500. What must it do?

A. Send the colour red to memory

B. Send address 500 to memory and signal a read

C. Ask the monitor to search for the address

D. Wait for the keyboard to supply the instruction

Question 130

The data bus carries:

A. Only memory addresses

B. Only timing signals

C. The actual data moving between CPU, memory and I/O devices

D. Electricity to the power supply

Question 131

Why is the data bus described as bidirectional?

A. It has two separate monitors

B. It carries two types of address

C. It works only when two computers are connected

D. Data can travel both to and from the CPU

Question 132

A computer's data bus is said to be 32 bits wide. This tells us how many bits:

A. Can be transferred at the same time

B. Memory can store in total

C. The monitor can display

D. The hard disk can hold

Question 133

The address bus carries:

A. The data itself

B. The location of the data or instruction to be accessed

C. The results printed on paper

D. The power for the CPU

Question 134

In which direction do addresses travel on the address bus?

A. From memory to the monitor

B. From the keyboard to the printer

C. From the CPU to memory or I/O devices

D. In both directions equally

Question 135

A wider address bus allows the CPU to:

A. Print faster

B. Display more colours

C. Use fewer instructions

D. Address a larger number of memory locations

Question 136

The control bus carries:

A. Control and timing signals that coordinate the components

B. Files stored on the hard disk

C. Memory addresses only

D. The results shown on the monitor

Question 137

Which of the following is sent on the control bus?

A. The value 25 to be stored

B. A memory read signal

C. The address 1000

D. The colour of a pixel

Question 138

Why is the control bus needed when the CPU communicates with memory?

A. To store extra data

B. To supply electric power to memory

C. To tell memory whether to read or write and when

D. To connect the keyboard to the monitor

Question 139

The CPU wants to read the data stored at memory location 2000. Which description of the transmission is correct?

A. Data bus sends 2000; address bus returns the data

B. Control bus sends the data; address bus sends the read signal

C. Only the data bus is used for everything

D. Address bus sends 2000, control bus sends the read signal, and the data bus returns the data

Question 140

One line of a computer's address bus is damaged. What is the most likely problem?

A. The CPU may access wrong or unreachable memory locations

B. The monitor will change colour

C. The keyboard will type in another language

D. The printer will print faster

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