1.1 Number Systems Cambridge IGCSE 0478

Why do computers use binary to represent all forms of data?

• Computers process data using logic gates that operate on binary values.

• Binary is the most efficient way for humans to understand numbers.

• Denary numbers take up too much memory in a computer.

• Binary is used because it has more digits than hexadecimal.

What is the base of the hexadecimal number system?

• 16

• 2

• 10

• 8

Convert the denary number 25 into binary.

• 11001

• 10101

• 11010

• 10011

What is the main advantage of using hexadecimal instead of binary?

• It is easier for humans to read and write.

• It uses fewer logic gates in processing.

• It requires less memory in storage.

• It allows more complex calculations.

What is the binary sum of 10111011 and 00001010?

• 11010000

• 10110110

• 11011111

• 10111100

What happens when a binary sum exceeds the maximum value that can be stored in a register?

• An overflow error occurs.

• The computer automatically increases the register size.

• The additional bits are ignored with no effect.

• The sum is stored as hexadecimal instead.

What is the result of performing a logical left shift on the binary number 00010100 by one place?

• 00101000

• 00001010

• 00010101

• 01010000

Which of the following best describes how two’s complement is used?

• It represents both positive and negative integers in binary.

• It is used for floating-point calculations only.

• It is an alternative to hexadecimal notation.

• It prevents overflow errors from occurring.

Convert the hexadecimal number 3F into binary.

• 00111111

• 01111110

• 11001100

• 11100011

What is the result of a logical right shift on 10011000 by two places?

• 00100110

• 00011001