Data Representation (Cambridge (CIE) AS Computer Science): Exam Questions

A computer system stores text, images and sound.

A character set is used to represent characters in a computer.

Identify and describe one character set.

Character set ....................

Description .......................

Convert the hexadecimal number 1FAB into denary.

Working ............................

Denary value .....................

Explain how to convert the two’s complement integer 10011111 into denary.

Give the denary value after conversion.

Explanation ......................

Denary value .....................

Complete the binary addition. Show your working.

1 0 0 1 1 1 1 0
0 1 1 0 0 0 0 1
+ 0 0 0 1 1 0 0 1

A computer stores binary data.

Tick (✓) one box only to identify the largest file size.

☐ 3300 kibibytes

☐ 0.3 megabytes

☐ 3 mebibytes

☐ 3300 kilobytes

Subtract the denary number 10 from the denary number 100 using binary subtraction.

Show your working.

Convert the hexadecimal number C0F into denary.

Show your working

Complete the following description.

A kibibyte has a ................................................ prefix. Three kibibytes is the same as ................................................ bytes.

A megabyte has a ................................................ prefix. Two terabytes is the same as ................................................ gigabytes.

Convert the denary number 241 to hexadecimal

State what is meant by an overflow in binary addition.

Computers use character sets when representing characters in binary.

(i) Complete the table by identifying the number of bits each of the character sets allocates to each character.

(1)

(ii) Explain how the word ‘Clock’ is represented by a character set.

(2)

State one difference between a kibibyte and a megabyte.

(i) Convert the denary value into a 12-bit two’s complement binary integer.

−196

(1)

(ii) Convert the Binary Coded Decimal (BCD) into denary.

100001100101

(1)

(iii) Convert the unsigned binary integer into denary.

000111010110

(1)

Identify one practical application of BCD and justify why BCD is used in this application.