CIE IGCSE COMPUTER SCIENCE EXAM
QUESTIONS AND ANSWERS
Simplex - Answer-Data flows in one direction
Half Duplex - Answer-Data flows in both directions, but only one direction at a time.
Full Duplex - Answer-Data flows in both directions at the same time
Denary system - Answer-number system based on the number 10
Binary system - Answer-Number system based on the number 2
Hexadecimal System - Answer-Number system based on the number 16. (Used for
memory dumps, HTML, MAC addresses, web addresses, and assembly code/machine
code)
Serial Transmission - Answer-Data is transmitted one bit at a time down a single wire.
Parallel Transmission - Answer-Data is transmitted several bits at a time using multiple
wires
Asynchronous Transmission - Answer-Data being transmitted in an agreed bit pattern
Synchronous Transmission - Answer-A continuous stream of data which is
accompanied by timing signals generated by an internal clock
Parity Bit - Answer-Created to eliminate data communication errors by indicating the
even or odd parity bit's validity.
Even Parity - Answer-1s in a set of data need to be made even.
Odd Parity - Answer-1s in a set of data need to be made odd.
Universal Serial Bus (USB) - Answer-- Asynchronous Serial Data Transmission
When plugged into computer:
- Device is detected
- If known device: automatically recognised; device driver is loaded
- If unknown device: Looks for correct device driver or user is prompted to download
the driver
Integrated Circuit (IC) - Answer-- Parallel Data Transmission
- Consists of fabricated transistors, resistors and capacitors
- Also known as a chip or microchip
, How can data be accidentally damaged? - Answer-Human error
- Misplacing computer / removable hard drive
- Forgetting to save
- Accidentally deleting a file
- Physical damage
System Failure
- Hardware Failure
- Antivirus Failure
- Software Crashing
- Power surge/failure
Accidental / Act of Nature
- Natural Disasters (Fire, Lightning Strike etc.)
- Floods (can be from a running tap)
- High/Low Ambient Temperature
Text-based passwords - Answer-- (A minimum number of) characters that can be typed
at a keyboard
- Is set and can be changed by the user
- Easier to hack than biometric passwords
- Stronger it is, the more difficult it is to hack (longer, more special symbols, random
etc.)
Biometric passwords - Answer-A stored, unique, human physical measurement
compared to a previously scanned measurement. e.g.:
- fingerprint scanner
- face recognition software
- retina scanner/iris scanner
- voice recognition software
Firewalls - Answer-- Can monitor incoming and outgoing traffic
- Can block unauthorized traffic
- Operate by checking traffic against a set of rules
- Can block access to certain websites
- Can be software or hardware
- Cannot act as intermediary servers
Software Firewalls - Answer-- Only protects one device
- Cheaper to configure
Hardware Firewalls - Answer-- Protect all devices in a network
- More expensive to configure
Proxy Servers - Answer-A computer system or application that acts as an intermediary
from clients seeking requests resources from other servers
QUESTIONS AND ANSWERS
Simplex - Answer-Data flows in one direction
Half Duplex - Answer-Data flows in both directions, but only one direction at a time.
Full Duplex - Answer-Data flows in both directions at the same time
Denary system - Answer-number system based on the number 10
Binary system - Answer-Number system based on the number 2
Hexadecimal System - Answer-Number system based on the number 16. (Used for
memory dumps, HTML, MAC addresses, web addresses, and assembly code/machine
code)
Serial Transmission - Answer-Data is transmitted one bit at a time down a single wire.
Parallel Transmission - Answer-Data is transmitted several bits at a time using multiple
wires
Asynchronous Transmission - Answer-Data being transmitted in an agreed bit pattern
Synchronous Transmission - Answer-A continuous stream of data which is
accompanied by timing signals generated by an internal clock
Parity Bit - Answer-Created to eliminate data communication errors by indicating the
even or odd parity bit's validity.
Even Parity - Answer-1s in a set of data need to be made even.
Odd Parity - Answer-1s in a set of data need to be made odd.
Universal Serial Bus (USB) - Answer-- Asynchronous Serial Data Transmission
When plugged into computer:
- Device is detected
- If known device: automatically recognised; device driver is loaded
- If unknown device: Looks for correct device driver or user is prompted to download
the driver
Integrated Circuit (IC) - Answer-- Parallel Data Transmission
- Consists of fabricated transistors, resistors and capacitors
- Also known as a chip or microchip
, How can data be accidentally damaged? - Answer-Human error
- Misplacing computer / removable hard drive
- Forgetting to save
- Accidentally deleting a file
- Physical damage
System Failure
- Hardware Failure
- Antivirus Failure
- Software Crashing
- Power surge/failure
Accidental / Act of Nature
- Natural Disasters (Fire, Lightning Strike etc.)
- Floods (can be from a running tap)
- High/Low Ambient Temperature
Text-based passwords - Answer-- (A minimum number of) characters that can be typed
at a keyboard
- Is set and can be changed by the user
- Easier to hack than biometric passwords
- Stronger it is, the more difficult it is to hack (longer, more special symbols, random
etc.)
Biometric passwords - Answer-A stored, unique, human physical measurement
compared to a previously scanned measurement. e.g.:
- fingerprint scanner
- face recognition software
- retina scanner/iris scanner
- voice recognition software
Firewalls - Answer-- Can monitor incoming and outgoing traffic
- Can block unauthorized traffic
- Operate by checking traffic against a set of rules
- Can block access to certain websites
- Can be software or hardware
- Cannot act as intermediary servers
Software Firewalls - Answer-- Only protects one device
- Cheaper to configure
Hardware Firewalls - Answer-- Protect all devices in a network
- More expensive to configure
Proxy Servers - Answer-A computer system or application that acts as an intermediary
from clients seeking requests resources from other servers
