Q&A-Data Representation in a Computer

Q1.

Give two reasons why hexadecimal is often used instead of binary in computer
science.

• hexadecimal is easier (for humans) to read (than binary);
• numbers are displayed in a more compact way (in hexadecimal than in binary);
• it is quicker to type in (hexadecimal numbers than binary numbers);
• it reduces the risk of typing errors (in hexadecimal numbers than binary numbers);

Q2.

A computer operates as a binary digital device. Explain why binary is used to represent computer data.

• Binary can represent two states because computer circuits use transistors, which can either be on or off

Q3.

A car park uses a number plate recognition system. Identify the reason why unsigned integers should be used to record the number of cars entering and leaving the car park, rather than signed integers

• Unsigned integers store more positive values

Q4.

A sound engineer is recording a singer. Describe why the sound must be converted to a digital format before it can be stored on a computer system

• Computer systems use binary/ones and zeros/voltage on or off;
• Sound is analogue/continuous;
• Computers use digital data/discrete values

Q5.

Elucidate the fact that zero can only be represented in one way in twos complement and in two ways in ones complement

Taking a four-digit 0  binary number i.e (0000)2

In ones complement this is  1111

In twos complement this becomes 1111+1= 0000

So, It is clear that 0 and negative zero is the same in twos complement while in ones complement they are two different values