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WorksheetsHigher Computer Systems
Total questions: 33
Worksheet time: 3mins
State which of the following denary numbers is represented as 10010111 using two's complement.
-105
151
-151
105
State which of the following denary numbers is represented as 11100110 using two's complement.
-26
26
230
-230
State which of the following 8-bit two's complement numbers represent the denary number -100.
10011100
00011100
01100100
11100100
State which of the following 8-bit two's complement numbers represent the denary number 60.
00111100
10111100
01100100
00111110
State the range of numbers that can be represented using 6 bit two's complement.
-32 to 31
-31 to 32
-16 to 15
-15 to 16
State the range of numbers that can be represented using 10 bit two's complement.
-512 to 511
-511 to 512
-1024 to 1023
-1023 to 1024
A floating point representation is assigned 16 bits. The mantissa is assigned 12 bits and the exponent is assigned 4 bits. State which of the following answers correctly represent -0.1101 x 2^101
Sign: 1
Mantissa: 11010000000
Exponent: 0101
Sign: 1
Mantissa: 00000001101
Exponent: 0101
Sign: 0
Mantissa: 11010000000
Exponent: 0101
Sign: 1
Mantissa: 110100000000
Exponent: 0101
A floating point representation is assigned 8 bits. The mantissa is assigned 4 bits and the exponent is assigned 4 bits. State which of the following answers correctly represent 0.0000110
Sign: 0
Mantissa: 110
Exponent: 1100
Sign: 1
Mantissa: 110
Exponent: 1100
Sign: 0
Mantissa: 110
Exponent: 0100
Sign: 1
Mantissa: 110
Exponent: 0100
State which statement describes the effect of changing the number of bits assigned to the mantissa.
Increase the number of bits: Precision increases
Decrease the number of bits: Precision decreases
Increase the number of bits: Precision decreases
Decrease the number of bits: Precision increases
Increase the number of bits: Range increases
Decrease the number of bits: Range decreases
Increase the number of bits: Range decreases
Decrease the number of bits: Range increases
State which statement describes the effect of changing the number of bits assigned to the exponent.
Increase the number of bits: Precision increases
Decrease the number of bits: Precision decreases
Increase the number of bits: Precision decreases
Decrease the number of bits: Precision increases
Increase the number of bits: Range increases
Decrease the number of bits: Range decreases
Increase the number of bits: Range decreases
Decrease the number of bits: Range increases
State which of the following are advantages of using Unicode compared to ASCII.
Unicode can represent more characters as it uses 16 bits compared to 8 bits.
Unicode can represent many languages allowing for one standard method of communication.
Unicode has a larger file size as it uses 16 bits compared to ASCII which only used 8 bits.
ASCII is commonly used across the world to represent multiple languages.
State which of the following are advantages of using a vector graphic over a bit-mapped graphic.
Smaller File Size
Resolution Independent
Images often don't look real and have a cartoon feel to them.
Larger File Size
Adding detail won't increase the file size
State which of the following are advantages of using a bit-mapped graphic over a vector graphic.
Can be used to store realistic photographs
Can edit individual pixels
Adding detail won't increase the file size
Smaller File Size
Resolution Dependent
State which of the following are disadvantages of using a vector graphic over a bit-mapped graphic.
Adding detail will increase the file size
Resolution Independent
Images often don't look real and have a cartoon feel to them
Larger File Size
Adding detail won't increase the file size
State which of the following are disadvantages of using a bit-mapped graphic over a vector graphic.
Larger File Size
Can edit individual pixels
Graphics cannot be layered
Smaller File Size
Resolution Dependent
Describe the concept of the fetch-execute cycle.
The fetch-execute cycle describes the process of the CPU retrieving instructions from RAM and carrying them out.
The fetch-execute cycle describes the process of the CPU retrieving instructions from backing storage and carrying them out.
The fetch-execute cycle describes the process of the CPU decoding instructions.
The fetch-execute cycle describes the process of the CPU retrieving instructions from backing storage and passing them to RAM to be executed.
State which of the following factors improve a systems performance.
Higher number of processing cores
Higher amount of RAM
Decreasing amount of cache memory
Increased clock speed
Decreased width of the data bus
Describe the term "cache memory".
Cache memory stores frequently executed instructions. Cache memory can be accessed quickly but its capacity is smaller than RAM.
Cache memory stores a cache of common answers to questions that the user searches using a search engine.
Cache memory is used to store website that people commonly use that that they can be loaded faster.
Cache memory is a type of memory that is accessed after RAM but before the backing storage so that commonly used instructions can be accessed faster.
Describe the term "width of data bus".
The data bus carries data between the CPU and other components. The larger the width, the more data can be transferred at a time.
The data bus carries address between the CPU and RAM. The larger the width, the more addresses can be transferred at a time.
The data bus connects components together and tells them what to do. The larger the width, the more commands the data bus can have.
The width of the data bus describes how many wires are in the bus. With a smaller numbers of wires the data bus can be more efficient and carry more data at one time.
Explain the effect of increasing the number of cores in a computer system has on the performance of a computer system.
The computer system's performance increases as each core can carry out one instruction at a time. With more cores, more instructions can be carried out at one time.
The computer system's performance decreases because as you add more cores the computer system will have to use more electricity to power the cores.
Each core contains one ALU, one Control Unit and one set of registers.
The computer system's performance increases because as you increase the number of cores, the clock speed will increase and as you increase the clock speed the performance improves.
Describe the term "Clock Speed"
Clock Speed refers to the number of times the clock line on the data bus turns on per second. When the clock line turns on all the components are told to execute the next instructions.
As you increase clock speed the performance of the computer system will improve as the clock speed dictates the number instructions that can be carried out per second.
The speed of the clock is one second.
In a computer there is a component called the clock which tells the other components when to carry out the next instruction. As you increase the number of clocks, the clock speed increases to tell the other components to carry out more instructions per second.
Which of the following would be considered as illegal using the Computer Misuse Act 1990?
Accessing your friends computer to get read an essay he wrote without their knowledge.
Changing a games source code to allow you to have cheats in the game.
Using your work computer to read your bosses emails as part of your job.
A business not keeping their customers data safe on their server.
Using your phone to access a public wifi network without a password.
Describe the purpose of the Computer Misuse Act 1990.
The Computer Misuse Act was created to protect computer users against intentional attacks and theft of information.
The Computer Misuse Act was created to protect computer from being stolen.
The Computer Misuse Act is a piece of legislation that only stops hackers from creating malware.
The Computer Misuse Act was created in 1990 in response to the first computer worm created, the Morris Worm, in 1988. The act was initially designed to stop malware from being released on the internet.
Describe the term "Tracking Cookies".
Tracking cookies are used track which websites you access and what you click on. This information is then shared with a company who can use this to create targeted ads.
Tracking cookies are always a security risk that can steal your personal data to sell to the highest bidder.
Tracking cookies are used by hackers to track what a target is doing so that they can set up malware to capture their passwords.
Tracking cookies are used to remember your username and passwords so that a hacker can retrieve them later and log in to your accounts.
State the purpose of a DoS attack.
A DoS attack is when a computer is used to send lots of requests to a server in an attempt to stop it from being able to service the legitimate users.
A DoS attack is when many computers are used to send lots of requests to a server in an attempt to stop it from being able to service the legitimate users.
A DoS attack is when a hacker will attempt to access a server to steal the data stored on it.
Denial of Service is when a Domain Name Server breaks which causes many internet users to no longer be able to access the websites they want to visit.
State which of the following are symptoms of a DoS attack?
Slow Performance
Inability to access service
Loss of data
Lost revenue
Bandwidth consumption
State the types of fault that can be used to carry out a DoS attack.
Bandwidth Consumption
Resource Starvation
DNS Attack
Data Centre Flood
Botnet Amplification
Describe the purpose of a digital certificate.
A digital certificate is used to verify that a public key is actually from the person it says it is from.
A digital certificate is used to verify who sent the encrypted message.
A digital certificate is used to verify that a private key is actually from the person it says it is from.
A digital certificate is used on a website to prove that any data sent to and from the web server is encrypted.
State the steps of sending encrypted data using public-key encryption.
The sender uses their private key to encrypt the data first. They then use the receiver's public key. When the receiver gets the data is then decrypting using the receiver's private key followed by the sender's public key.
The sender uses their public key to encrypt the data first. They then use the receiver's private key. When the receiver gets the data is then decrypting using the receiver's public key followed by the sender's private key.
The sender uses their public key to encrypt the data first. They then use the receiver's public key. When the receiver gets the data is then decrypting using the receiver's private key followed by the sender's private key.
The sender uses their public key to encrypt the data first. They then use the receiver's public key. When the receiver gets the data is then decrypting using the receiver's private key followed by the sender's private key.
State which of the following statements are true.
An intelligent system is a computer system that interacts with the real world using sensors and other digital components.
An intelligent heating system can reduce environmental impact by linking with a weather system to help adjust the usage of radiators in a building.
An intelligent car management system can reduce the environmental impact of driving a car by choosing a route to the destination that has the least traffic.
An intelligent traffic control system is used to keep traffic moving so that the cars aren't drastically changing speed.
The number of bits needed to represent the denary number 512 using two's complement is: (a)
A floating-point number uses 12 bits to store itself in the computer. The mantissa was originally assigned 8 bits and the exponent 4 bits but it was found that the computer could not store large enough numbers. What should be done to store larger numbers?
Increase the number of bits assigned to the exponent, this will decrease the number of bits assigned the the mantissa.
Increase the number of bits assigned to the mantissa, this will decrease the number of bits assigned the the exponent.
To increase the range of the numbers we must increase the number of the bits to the mantissa so that it can store a larger number.
We should increase the number of bits used to 16 bits.
State the purpose of a Digital Signature.
To prove that the data has not been altered in transit.
To agree to a digital contract.
To prove that the public key is from the right person.
To lock the attached file so that it cannot be opened.
