Second year test

Question 1

What is normalisation?

Answer 1

Every attribute is dependent upon the key, the whole key and nothing but the key

Question 2

What is 1st normal form?

Answer 2

Stops repeated groups

Question 3

What is 2nd normal form?

Answer 3

Partial key dependence test

Question 4

What is 3rd normal form?

Answer 4

non-key dependence test

Question 5

Why is normalisation important?

Answer 5

reduces data duplication

eliminates data inconsistency

Question 6

What SQL commands are there?

Answer 6

Select
From
Where
Order By
And
Insert Into
Update
Delete from 
Create

Question 7

What is record locking?

Answer 7

A technique to prevent updates being lost or inconsistencies in data rising. Database is locked until table has been edited and updated.

Question 8

What is underflow?

Answer 8

When number is too close to 0 to be represented

Question 9

What is overflow?

Answer 9

a number is too big to be represented in a given number of bits

Question 10

What is cancellation error?

Answer 10

When a sum is between two numbers of a very different size

Question 11

What is a recursive route?

Answer 11

A route that is defined in terms of itself

Question 12

What is an intractable problem?

Answer 12

Can be solved by a computer, but cannot be solved in a reasonable time for large inputs. Anything less than O(n^2)

Question 13

Example or logarithmic time

Answer 13

Binary search

Question 14

Example of Linear time search

Answer 14

Linear search

Question 15

Example of quadratic time search

Answer 15

Bubble sort

Question 16

Example of exponential time search

Answer 16

Fibonacci algorithm

Question 17

example of Factorial time

Answer 17

travelling salesman problem

Question 18

What is serial data transmission?

Answer 18

Data is sent, one bit at a time, across a single wire

Question 19

What is parallel data a transmission?

Answer 19

Several bits are sent simultaneously over a number of parallel wires. Short distances.

Question 20

Why is serial better for longer distances?

Answer 20

In parallel, interference(skew) can occur at high frequencies

Question 21

What is the baud rate?

Answer 21

the rate at which the signal changes?

Question 22

What is the bit rate of a channel?

Answer 22

(baud rate)x(number of bits per signal)

Question 23

What is bandwidth?

Answer 23

The range of signal frequencies that a medium can transmit. The greater the bandwidth, the greater the potential bit rate.

Question 24

What is latency?

Answer 24

The time delay when a component is responding to an instrument

Question 25

What is the purpose of a parity bit?

Answer 25

To detect errors in code

Question 26

What is a protocol?

Answer 26

A set of rules relating to communication between devices

Question 27

What is Asynchronous transmission?

Answer 27

A transmission which only synchronises for the duration of the transmission by sending start and stops bits

Question 28

What is a LAN?

Answer 28

A number of computing devices connected by cables. Sends data very fast over a short distance

Question 29

Advantages and disadvantages of a bus topology

Answer 29

Advantages) Less cable and doesn’t require additional hardware
Well suited to small networks, low speed
Disadvantages) If main cables fails, whole network goes down
Limited cable length and amount of stations
Performs degrades with heavy traffic
Low security, all computers on network can see transmissions

Question 30

What is the fetch execute cycle symbols?

Answer 30

MAR