Questions Paper 2 Flashcards
Convert the decimal 197 into binary
11000101
Convert the hexadecimal number A4 into decimal.
Show your working
16 = 1
10 = 4
160 and 4
160+4 = 164
What is the largest decimal number that can be represented using 5 bits.
11111
How many bits are there in 3MB?
3MB = 3 * 1000 = 3000KB
3000kB * 1000 = 3,000,000
3,000,000 * 8 = 24,000,000
State one advantage of using Unicode instead of using ASCII
Unicode covers all major languages, it uses multiple bytes for each character.
Which two are components of a CPU?
Arithmetic Logic Unit
Control Unit
A computer game is one type of application software. State two other types of application software. You must not use brand names in your answer.
- Word Processors
2. Web browsers
What is true about secondary storage?
Secondary Storage is non volatile
Describe how an optical disk is read?
Optical discs use a laser to scan the surface of a spinning disc.
The disc surface is divided into tracks, with each track containing many flat areas (lands) and hollows (pits).
When the laser shines on the disc surface, lands reflect the light back, whereas pits scatter the laser beam.
A sensor looks for the reflected light
Reflected light represents a binary ‘1’ and no reflection represents a binary ‘0’
what string does this encoding represent?
LEAST
What would be the correct binary encoding for the substring STAR?
1010 , 1011, 00, 01
Define the term embedded system
Embedded systems are computers built into other devices, like dishwashers. They are usually dedicated systems. Embedded systems are often used as control systems - they monitor and control machinery in order to achieve the desired result.
Explain three different electronic methods that could then be used to confirm user identity.
Passwords - simple methods of checking someone’s identity. They are strong and uses a combination of letters, numbers and symbols. Weak passwords are a big security risk.
Biometric measures use scanners to identify people by a unique part of their body, e.g fingerprint. They prevent unauthorised access and are quite secure and convenient but are usually more expensive as they require special hardware.
Email confirmation is used by most web services that require account registration to confirm that the email address belongs to the person. It is used to stop people from using fake email addresses to sign up for things.
Penetration testing can be conducted as either black box or white box testing.
Explain the difference between these two types of penetration testing.
White box stimulates malicious insider who has knowledge of the current system whereas black box stimulates an external cyber attack.
WB- the person carrying out the test will be given user credentials to see what they can do with them whereas BB the person will not be giving any credentials but will try to hack the organisation in any way they can.
Describe 3 different categories of malware.
Worms - like viruses but self replicate without any user help, meaning they can spread very quickly. They exploit weaknesses in network security.
Trojans - malware disguised as legitimate software. Trojans do not self replicate - users install them not realising they have a hidden purpose.
Spyware - Secretly tracks actions like key presses and sends info to the hacker, who might be able to work out things like passwords and bank details.
