Computer systems sample exam questions

Convert the following 16-bit two’s complement number into denary: 1111 0 1110 1011

• -21

• -19

• -37

• -13

A website is subject to a DOS attack. What are two symptoms users experience when this happens?

• Slow website response time and inability to access the website

• Improved website performance and faster loading times

• Increased security and protection from hackers

• Enhanced user experience and better website design

Convert 0·001011 to floating-point representation. There are 16 bits for the mantissa and 8 bits for the exponent.

• 0 01111100 0010110000000000

• 0 01111101 0010110000000000

• 0 01111110 0010110000000000

• 0 01111111 0010110000000000

Two computer systems have the same number of processor cores, the same width of data bus and the same clock speed. (a) State one other factor that could account for one computer system performing better than the other, when tested for processing speed. (b) Explain why increasing the width of the data bus will improve the system performance.

• (a) Amount of RAM; (b) It allows more data to be transferred at once, increasing throughput.

• (a) Type of keyboard; (b) It reduces the power consumption of the system.

• (a) Color of the casing; (b) It improves the aesthetic appeal of the system.

• (a) Brand of the monitor; (b) It enhances the display quality.

The role of public and private keys when transferring secure data is to:

• Encrypt data for secure transmission and decrypt it upon receipt.

• Store data securely on a server.

• Transfer data without encryption.

• Ensure data is only accessible to the public.

The BigIQ Company stores the results for an intelligence test in an external csv file. The data includes each participant’s unique ID number, name, town and score. An extract, is shown below. A participant manages to access the file and change their own score. State two different offences the participant has committed under the Computer Misuse Act 1990.

• Unauthorized access to computer material and unauthorized modification of computer material

• Unauthorized access to computer material and unauthorized access with intent to commit further offences

• Unauthorized modification of computer material and unauthorized access with intent to commit further offences

• Unauthorized access to computer material and unauthorized access to computer systems

The web page uses bit-mapped graphic files for the book covers. State one advantage of using bit-mapped graphic files rather than vector graphic files on this web page.

• Bit-mapped graphics are more scalable.

• Bit-mapped graphics have smaller file sizes.

• Bit-mapped graphics provide more detailed images.

• Bit-mapped graphics are easier to animate.

One of the book descriptions contains Unicode characters. State one advantage of using Unicode characters rather than ASCII characters in web pages.

• Unicode supports a wider range of characters and symbols.

• Unicode is faster to process than ASCII.

• Unicode is more secure than ASCII.

• Unicode uses less memory than ASCII.