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Flashcards in Revision notes OCR Deck (27)
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1
Q

For a digital camera, state:

a) two input devices (2 marks)
b) two output devices (2 marks)
c) one storage device. (1 mark)

A

a) Examples (2 to be given): buttons; light-sensitive, CCD,
CMOS chip; microphone
b) Examples (2 to be given): screen; speaker; flash
c) Example (1 to be given): card reader

2
Q

Why does a computer have both ROM and RAM? (2 marks)

A

ROM is needed for the initial settings and boot sequence;
RAM is needed to store data and programs in use.

3
Q

What is in RAM when the computer is working? (3 marks)

A

Operating system; programs; data in use by programs

4
Q

How does the use of virtual memory affect the performance of a computer? (3 marks)

A

Data is swapped between RAM and the hard disk; hard disk
access is slower than RAM access, which slows access to data;
performance is slower because transferring data is slow.

5
Q

How would installing extra RAM affect the use of virtual memory and
what effect does this have on the performance of the computer? (2 marks)

A

More RAM means fewer data transfers to virtual memory and
improved performance.

6
Q

What is the purpose of the CPU? (1 mark)

A

The CPU carries out processing on the computer; it fetches
and executes instructions.

7
Q

What is meant by ‘2.5 MHz quad core’ when describing a processor? (4 marks)

A

The CPU clock speed is 2.5 MHz (2.5 million instructions
can be processed per second); it has 4 cores (4 independent
processors working together).

8
Q

State one advantage and one disadvantage of a dual-core processor over a
single-core processor. (2 marks)

A

Advantage: A dual-core processor can process data
simultaneously, so faster. Disadvantage: A more complicated
operating system is needed; it is harder to write software for
multiple processors.

9
Q

Identify two input devices and two output devices on a mobile phone. (4 marks)

A

Input examples (2 to be given): touch screen; microphone;
accelerometer; light sensor; buttons; camera
Output examples (2 to be given): touch screen; speaker; motor
(to make the phone vibrate)

10
Q

Identify, with reasons, three devices that would help a visually impaired
person to use a computer. (6 marks)

A

Examples (3 to be given): Braille keyboard – raised dots
to identify symbols; speaker and voice synthesis to read
documents; microphone with voice recognition to issue
commands

11
Q

Determine the output from each of the following logic circuits:

A

a) P = 1
b) Q = 1
c) R = 0
d) S = 1
e) T = 0
f) V = 1

12
Q

Copy and complete the truth table for the circuit in Figure 2.11. (16 marks)

A
13
Q

Why does a computer need secondary storage? (2 marks)

A

Secondary storage is needed to store data and programs when
the power is switched off because RAM is volatile and loses
contents when there is no power.

14
Q

What is the most suitable type of secondary storage for:

a) transferring work between home and school (1 mark)
b) distributing a software application (1 mark)
c) storing work and programs on a large school network (1 mark)
d) storing images in a digital camera? (1 mark)

A

a) USB flash memory drive
b) CD ROM
c) Hard disk drive
d) Flash memory card.

15
Q

State two reasons why an operating system is necessary in a computer. (2 marks)

A

An operating system hides the complexities of the hardware
and allows the user to operate the computer without having
to write programs.

16
Q

Explain the relationship between an application and an operating system. (2 marks)

A

An application performs a useful real-world job; an operating
system controls the hardware.

17
Q

List three maintenance actions that can be achieved with a typical
operating system GUI. (1 mark)

A

Examples (3 to be given): copying files; selecting software;
controlling sound volume; connecting to WiFi; deleting
files; moving files; checking battery state; updating software;
installing new software

18
Q

Explain why voice input is still an underdeveloped area for user interface
development. (3 marks)

A

Any 2 of: problems with accents, speed of talking, dialects

19
Q

Define the term ‘user interface’. (2 marks)

A

The user interface is the boundary between the computer
and users.

20
Q

Explain why computer technicians often use the command line in order
to carry out system maintenance. (3 marks)

A

Examples: greater control; able to group commands; quicker
to operate than a GUI

21
Q

Explain the advantages of using a GUI to interact with a phone. (3 marks)

A

Examples: difficult to type on small on-screen keyboard;

no need to learn commands; suitable for non-specialist; can make use of touch screen technology; extra touch facilities available, such as pinch or tap

22
Q

Explain the term “Interrupt”

A

a signal/request generated by a device/program

causes a break in execution of a program/stops the program

e.g printer out paper, pressing break key

23
Q

Explain the term ‘byte’

A

fixed number of bits/8 bits

represents a character

unit of memory/storage

e/g 11010001

24
Q

Explain the term CD-ROM

A

(secondary/portable) storage medium

can be read only (memory)

cannot change data

e.g. used to store programs/data/picutres/films, etc

25
Q

Explain the term ‘buffer’

A
  • temporary store/memory
  • allows speed of CPU/devices to be matched
  • to hold data being transferred between peripherals and CPU

e.g pages stored waiting to be printed

26
Q

Differences between high level and low level languages

A

high level

  • portable
  • problem-oriented
  • close to English
  • one-to-many relationship
  • easier to debug/change/update
  • needs compiler/interpreter

low level

  • machine-oriented
  • can be difficult to read
  • one-to-one relationship
  • needs assembler
27
Q
A