standard questions

Question 1

why do computers use binary

Answer 1

• it is the simplest method for counting available.
• It is how computer code everything.
• binary allows for computer to proceed millions of inputs very quickly.

Question 2

reasons for using hexadecimal?

Answer 2

-provides a shorter way to represent a byte of data.
-it uses memory, more efficiently

Question 3

what is the ASCII code?

Answer 3

it is the international agreed standard for coding a computer.
it is out link between our computer screen and computer hardware.
used to translate computer text to human text.

Question 4

examples of ASCII codes?

Answer 4

-web address
-URL

Question 5

what is sampling resolution

Answer 5

-The number of bits assigned to each sample. -Also known as bit depth.

Question 6

what is sampling rate?

Answer 6

The number of samples taken in a second.

Question 7

why does Sound need to be converted into binary?

Answer 7

For computers to be able to process it.

Question 8

sound needs to be converted into binary for computers to be able to process it. How is this done?

Answer 8

sound is captured (by a microphone), and then converted into a digital signal. And analogue to digital converter will sample a sound wave at regular time intervals.

Question 9

how do you calculate file size?

Answer 9

Pixel high x pixel wide x color depth
Divided by 8 × 1024

Question 10

how do you calculate the size of a sound file?

Answer 10

mono = sample rate x sample size x time
stereo = sample rate x sample size x time (x2)

Question 11

what is data compression?

Answer 11

• Is the reduction in the number of bits needed to represent data.
• Is a method in which the logical size of a file is compressed

Question 12

what are advantages of compressing data?

Answer 12

• Save storage
• speed up file transfer
• reduce redundancy in stored data

Question 13

what is Lossy file compression?

Answer 13

bigger compression
smaller quality
When a file is compressed, data is permanently removed

Question 14

what is lossless data compression?

Answer 14

smaller compression
higher quality
When a file is compressed and restored no data is lost or removed

Question 15

what is data transmission?

Answer 15

Is the transfer of data of a point to point (or multipoint) communication channel

Question 16

What is serial data transmission?

Answer 16

• is a form of data transmission were bits of characters are sent one at a time along a communication path
• serial data transmissions travel over a single wire in one direction

Question 17

what are advantages and disadvantages of serial data transmission?

Answer 17

advantage - travels over a single wire at much less cost

disadvantage - Slower than parallel data transmission

Question 18

what is parallel data transmission?

Answer 18

Is a transmission of data where several bits are transmitted simultaneously, each along its own separate channel or multiple channels

Question 19

what are advantages and disadvantages of parallel data transmission?

Answer 19

Advantage - faster then serial

disadvantage - not appropriate for long distance. Data transmission
- can be expensive.

Question 20

what does CPU stand for? and what does it do?

Answer 20

• CPU is a central processing unit
• A CPU is the portion of a computer that retrieves and executes instructions

Question 21

what is an output device?

Answer 21

A device that receives or displays output from a computer system

Question 22

What are examples of output devices?

Answer 22

• monitors
• Printers
• speakers
• projectors

Question 23

what are examples of input devices?

Answer 23

• microphone
• Keyboard
• Mouse

Question 24

what is application software?

Answer 24

Computer programs written for specific purpose

Question 25

what is system software?

Answer 25

Programs that manage the operation of the computer
e.g. windows