Comp Sci Mock

Question 1

What is underflow?

Answer 1

A calculation too close to 0 to be represented in a given number of bits

Question 2

What is overflow?

Answer 2

A calculation too large to be represented in a given number of bits

Question 3

what is cancellation error?

Answer 3

Where addition or subtraction takes place with number of very different sizes

Question 4

what is absolute error?

Answer 4

Number required-Number represented

Question 5

What is relative error?

Answer 5

absolute error/number required

Question 6

Why do we normalise floating point values?

Answer 6

Ensure only one representation of a number

Question 7

What is the range in floating point?

Answer 7

The amount of numbers it can represent.

Question 8

What is precision in floating point?

Answer 8

How close to you can get to representing complex numbers like 110111011. More bits = More precision

Question 9

What is the largest and smallest number you can represent with a 6bit mantissa 4 bit exponent?

Answer 9

Largest 0.11111 0111

Smallest 1.00000 0111

Question 10

How would you represent A AND B using logic notation?

Answer 10

A.B

Question 11

How would you represent A OR B in logic notation?

Answer 11

A+B

Question 12

How would you represent Not A in logic notation?

Answer 12

Ā

Question 13

What values makes an XOR true?

Answer 13

01 and 10

Question 14

What is DeMorgan’s Law?

Answer 14

Break the line, change the sign

Question 15

What is Analogue Data?

Answer 15

Data that varies in a continuous manner

Question 16

What is Digital Data?

Answer 16

Data that takes the form of discrete values

Question 17

What does a ADC do?

Answer 17

Converts analogue sound into digital signals that can be stored on a computer

Question 18

What does a DAC do?

Answer 18

Converts digital signals stored on a computer into analogue sound that can be played through devices such as speakers

Question 19

What is sampling rate?

Answer 19

The number of samples take per second. Measured in Hz

Question 20

What is sampling resolution?

Answer 20

The number of bits assigned to each sample

Question 21

What is the equation for file size for sound?

Answer 21

Sample rate* Sample resolution * Length of sound

Question 22

What is lossless compression?

Answer 22

Compression that doesn’t lose any accuracy and can be decompressed into an identical copy of the original data
(FLAC, WAV are examples for Audio. JPEG PNG for images) Uses Run length encoding which takes long repeated values such as 111111 and compresses it to (6-1) so six ones

Question 23

What is lossy compression?

Answer 23

Compression that loses file accuracy. Generally smaller than lossless compression. Finds audio data that is less audible to humans and discards it. Then stores the remaining data in an efficient manner.

Question 24

What is Nyquist’s theorem?

Answer 24

The sample rate should be at a frequency which is at least twice that of the highest frequency in the sampled signal

Question 25

What is MIDI?

Answer 25

Musical Information Data Interface. A way of representing sounds made by an instrument digitally. Information is stored such as volume, instrument and length of note. Is very flexible and easy to edit and has a smaller file size.

Question 26

How does an ADC work?

Answer 26

The analogue sound is sampled At regular intervals And stored as discrete values

Question 27

What is the role of the program counter?

Answer 27

Stores the address of the next instruction to be fetched

Question 28

What is the role of the accumulator?

Answer 28

Stores the results of instructions

Question 29

What is the role of the Current instruction register?

Answer 29

Holds the current instruction that is to be decoded

Question 30

What is the role of the memory address register?

Answer 30

Holds the memory addresses to be read or written to

Question 31

What is the role of the memory buffer register?

Answer 31

Holds the data item to be transferred to or from a memory location

Question 32

What is the role of the data bus?

Answer 32

A bidirectional bus that carries data between components

Question 33

What is the role of the Address bus?

Answer 33

A unidirectional bus from the processor that carries addresses to be read or written to

Question 34

What is the role of the control bus?

Answer 34

A bidirectional bus that carries control signals such as memory read or memory write.

Question 35

What is the role of the control unit?

Answer 35

Fetches decodes and executes instructions one at a time/ Decodes instructions and checks that signals have been delivered successfully

Question 36

What is the role of the Arithmetic logic unit?

Answer 36

Performs mathematical operations

Question 37

What are the roles of the registers?

Answer 37

Fast memory locations on the processor

Question 38

What happens in the decode execute process?

Answer 38

- Instruction is held in the current instruction register - Control unit decodes the instruction - Opcode identifies what the instruction does - Relevant part of the processor executes the instruction - Instruction result is stored in main memory or accumulator - Status register is updated

Question 39

What is the role of the status register?

Answer 39

A flag set or cleared based on the result of the last instruction