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18 - Final Test

1. How many bytes are there per character in a text file?

2. Which is the smallest of these data capacities?

2KB

4GB

2049 bytes

0.5 MB

3. Which formulae can be used to estimate the file size of an image?

number of pixels wide * number of pixels high * number of bytes per pixel * 1.1

number of pixels * 1.1

number of pixels * number of bytes per pixel

number of pixels wide * number of bytes per pixel * number of pixels * 1.1

4. Which formulae can be used to estimate the file size of a sound file?

bytes per sample * channels * height + number of minutes

samples per second * number of seconds * 1.1

samples per second * bytes per sample * duration

None of the above

5. How many bytes are needed to store 32769 different colours?

6. How many bytes are used in Unicode?

7. The ASCII code is represented using 16 bits

FALSE

TRUE

8. What is the maximum number of values that can be represented in 8 bits?

None of the above

256

9. What is the maximum number of values that can be represented in 7 bits?

100

128

10. A character set is the possible characters that can be represented by a computer system

TRUE

FALSE

11. The result of the binary addition 0110 + 0101 = 1011.

FALSE

TRUE

12. Overflow occurs when the pattern of bits is too small to be represented by the number of bits available in a register.

 It is also used to describe a machine code program that crashes.

FALSE

TRUE

13. 11010100 in binary would be E4 in Hex

FALSE

TRUE

14. What is 011 in Decimal?

15. What is 0000 in Decimal?

Error - you cannot have a binary number with only zeroes

16. What is this definition describing: The time period between taking samples/measurements. The more frequently the sound is sampled, the better the quality of playback

bit sampling

sampling of data

sample interval

sampling

17. A gigabyte is 1024 megabytes / 230 bytes

FALSE

TRUE

18. A nibble or nybble is 2 bits

TRUE

FALSE

19. Extended Binary Coded Decimal Interchange Code: an 8-bit character set used by older mainframes.

TRUE

FALSE

20. Short for picture element. It is the smallest component of a bit-mapped image.

bit

bit pattern

pixel

bitmap

21. Analogue to Digital converter: takes real-world analogue data and converts it to a binary representation that can be stored on a computer

ADC

DAC

None of the above

ADV

22. Data about data is referred to as:

knowledge

metadata

information

nonsense

23. What is a 106 in Hexadecimal?

123

24. 8 bits = 2 bytes

TRUE

FALSE

25. Sound waves are ________ which means they are continuously changing.

digital

high

mixed

analogue

26. The number of bits used to store each sample. The more bits used the better the accuracy of the sound file

sample resolution

sample rate

None of the above

sample interval

27. The largest value you can have with four bits is:

1111

1000

1101

1010

28. What is the result in binary after doing the left shift?

Binary Shift Example
=====================
The below number is no. 32 in Decimal. We want to multiply by 2.

Shift every bit to the left by one and insert a zero to the 
rightmost bit. The original leftmost bit is discarded.

128   64     32     16    8     4     2    1
=============================================
0     0      1     0     0    0    0    0

What is the Result in Binary?
======

128   64     32     16    8     4     2    1
=============================================
?     ?       ?      ?    ?     ?     ?    ?

1000000

11100101

11110001

10000000

29. If we wish to ______ we shift every bit to the left by one and insert a zero to the rightmost bit. The original leftmost bit is discarded.

add

subtract

multiply

divide

30. In decimal, you have the number 468, which is 111010100 in Binary. Shift it to the left to multiply by two and what happens?

Binary Shift Example
=====================
The below number is 468 in Decimal. We want to multiply by 2.

Shift every bit to the left by one and insert a zero to the 
rightmost bit. The original leftmost bit is discarded.

256   128   64     32     16    8     4     2    1
==================================================
1     1      1       0    1     0     1    0    0

What is the Result in Binary?
=============================
256   128   64     32     16    8     4     2    1
==================================================
???????????????????????????????????????????????????

It will add instead of multiply the numbers

Nothing spectacular. It will work as expected

You would get a result of 110101000 which is 424 - an overflow error has occurred

none of the above

31. In the following example, can you spot the error. We are trying to divide 8 using binary shift.

The video will help, but you do not need it to answer the question.                                    Binary Shift Example
=====================
The below number is 8 in Decimal. We want to divide by 2.

Shift every bit to the right by one.
The original rightmost bit is discarded.

256   128   64     32     16    8     4     2    1
==================================================
0     0      0     0      0     1     0    0    0

What is the Result in Binary?
=============================
256   128   64     32     16    8     4     2    1
==================================================
 0     0     0      0      1    0     0     0    0

two right shifts were necessary in order for the division to take place

a single left shift has been applied instead of a single right shift

a single right shift has been applied but the result has not been added to another bit of '1'

none of the above

32. Can you spot the error in this binary shift (division)?

Binary Shift Example
=====================
The below number is 16 in Decimal. We want to divide by 4.

4 is 2 to the power of 2 (so we shift of two times to the right)

Shift every bit to the right by two. The original rightmost bit is discarded.

256   128   64     32     16    8     4     2    1
==================================================
0     0      0     0      1     0     0    0    0

What is the Result in Binary?
=============================
256   128   64     32     16    8     4     2    1
==================================================
 0     0     0      0      0    0     1     0    0 

= 4 in Decimal.

The shift should have been just once to the right

The shift should have been one to the right, and the right most bit should not have been discarded but added to 1

There is no error. The calculation and shift has been performed correctly

The shift should have been one twice to the left, not right.

33. What statement is true about this lossy compression of images?

None of the above

They are vastly different and hugely matter

Compression has reduced the quality by a significant degree and should not be used

It is slightly more blurry but not enough to matter in most circumstances

34. What is the benefit of compressing an image file for a use on a website?

It may offer the user speed in loading the page for a very slighy quality reduction

All of the above

It takes up less storage space on your website

it would render five times faster

35. A film could take up to an hour to download in uncompressed format whilst a compressed file could take just 12 minutes

TRUE

FALSE

36. Lossless compression is when…

reducing file size with an increase in quality

reduing a file's size in exactly the same was as lossy compression

reducing file size with a massive reduction in quality

reducing a file's size with NO loss of quality

37. Fill in the blanks for RLE

RLE
===================================================
One of the simplest examples of compression is RLE. 
RLE is a basic form of data compression that converts 
consecutive identical values into a code consisting of
 the character and the number __________________________________.
The more similar values there are, the more values can be compressed. 
The sequence of data is stored as a single value and count.

marking the length of the run.

marking the number of bits contained in the file

marking the number of times the file has been compressed

marking the binary file size

38. In the following picture we compress …

consecutive pixels by only replacing each run with one pixel from it and a counter showing how many items it contains.

random pixels by replacing each run by four pixels from it.

random pixels by replacing each run with several pixels from it

nothing at all

39. Run-length encoding isn’t a very effective option when compressing texts, but for images …

where short runs of text bits happen to occur in sequence, it is useful

where long runs of the identical pixels happen to occur it is quite useful.

where there are pixels it is even less useful

None of the above

40. In "Peter Piper picked a peck of pickled peppers" the total no. of characters is ….

22 (excluding spaces)

44 (including spaces)

23 (including spaces)

33 (spaces are never included in calculations)

41. A group of four bits, or half a byte, is sometimes called a ____________________

byte or bit

kilobyte or megabyte

terrabyte or gigabyte

nibble or nybble.

42. 1 byte refers to …

2 bits

5 bits

1 bit

8 bits

43. 1 byte can be used to store

page of text from a novel

a number from 0 to 255

114 minutes of DVD Video

one mp3 song

44. This shows a memory stick with….

16 GB of memory

No memory

16 bytes of memory

32 bits of memory

45. bits, bytes, megabytes, gigabytes, terabytes etc are all used to…

describe disk space, data storage or the capacity of system memory

create the mother board

hold the parts of a computer together

perform calculations and store memory

46. A bit can be used to:

store a single letter like A

store a single number up to the value of 255

hold the answer to a yes/no or true/false question

store a single number up to the value of 55

47. A byte can be used to

store a single letter like A

store the letter 'C'

store a number from 0 to 255

all of the above

48. The symbol for byte is uppercase B. 16 bytes would be written as

16B

16Bi

16BYTES

16MB

49. A kilobyte is thought of as approximately 1000 bytes but to be accurate it is:

2024 bytes (which is 2 to the power of 10)

1024 bytes (2 to the power of 10)

12 bytes

102 bytes

50. Have a look at the table below which shows the units of information leading to memory. Fill in the blanks

1024 TB

None of the above

1000 Bytes

1024 GB

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