GCE O-Level · Computing (7155)

Data Representation: Practice Questions

5 multiple-choice questions marked as you go, and 5 written questions with worked solutions. All on Data Representation.

10 questions24 marksFree, no account

Question 1

1 mark

Which of the following represents the denary value 43 in 8-bit binary?

Question 2

1 mark

A specialized digital sensor uses a 6-bit two's complement system to represent temperature readings. What is the denary value of the largest positive integer that can be represented in this system?

Question 3

1 mark

Consider an 8-bit two's complement system. What is the result of the binary addition \(01011010 + 11010011\) in denary?

Question 4

1 mark

What is the denary equivalent of the 8-bit unsigned binary number 01011010?

Question 5

1 mark

Perform the binary addition: \(01101100 + 00111010\). What is the result in denary?

Question 6

2 marks

State the hexadecimal representation of the denary number 255 and explain how you arrived at the answer.

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Question 7

4 marks

Identify the 8-bit two's complement binary representation for the denary value \(-128\). Justify your answer briefly.

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Question 8

5 marks

A digital system uses 8-bit two's complement. If the binary value is \(1000\,0101_2\), determine its denary value by showing the weight assigned to the Most Significant Bit (MSB).

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Question 9

3 marks

Explain how computers use 8-bit extended ASCII to represent the English word "CODE". Your explanation should include:
(a) The process of how each character is stored as a bit pattern.
(b) Why 8 bits are sufficient for the extended ASCII character set compared to standard ASCII.

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Question 10

5 marks

Binary representation of signed and unsigned integers is essential for computer processing.

(a) State the maximum positive denary value that can be represented in an 8-bit two's complement binary system.
(b) Determine the 8-bit two's complement representation of the denary number \(-45\). Show your steps.
(c) Using 8-bit two's complement binary addition, add the binary value of \(-45\) from part (b) to the binary value of \(-20\) (given as \(11101100_2\)). State the resulting 8-bit binary value and whether an arithmetic overflow occurs.

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