Ict mixed questionsWatch this thread
- - A binary number system is a base- 2 number system which uses values from 0 to 1 whereas a denary number system uses values from 0 to 9.
- - Units in the binary number system is increased by a power of 2 whereas units in the denary number system increases by the power 10.
- - For the same value, the binary number system uses more digits as compared to denary number system.
Explain what is meant by HTML?
HTML stands for hypertext markup language. It is used to create webpages. It is translated by a browser to display webpages to the user.
Describe what is meant by structure and presentation?
Structure – refers to the layout of the context being displayed.
Presentation refers to the formatting of the content such as content color/style.
Explain the function of the web browser?
A web browser is used to display web pages by interpreting and translating a HTML document. It also provides functions such as bookmarking webpages and saving webpage URL’s in its history.
What are the uses of hexadecimal system?
Web Addresses (ASCII codes)
Assembly code / machine code
What does the first and last six digits of the MAC address represents?
First six digits – manufactures ID
Last six digits – serial ID
State why MAC addresses are used?
To uniquely identify a device connected to the internet.
Name three busses found in the Von Neumann architecture
- - Address bus (unidirectional)
- - Data bus (bi directional)
- - Control bus (unidirectional & bi directional)
Name the registers found in the Von Neumann architecture
- - Memory address register (MAR)
- - Memory data register (MDR)
- - Arithmetic and logic unit (ALU)
- - Program counter (PC)
- - Current Instruction register (CIR)
What is the function of the control unit?
The control unit is part of the computer’s CPU and is responsible for processor, memory and I/O operations. It interprets a program’s instructions and then sends signals to the computer’s memory, arithmetical logical unit and input/output devices telling them what to do.
- Address bus – this uni-directional bus carries signals relating to memory addresses between processor and memory. - Control bus – this bus carries signals used to coordinate the computers activities
- Data bus – this bi-directional bus is used to exchange data between processor, memory and input/output devices.
What is an interrupt?
It is a signal sent from a device to the processor requesting its attention.
What is a buffer?
It is a temporary memory area in a device.
How jpeg image will deduct reduction of file process?
Human eyes do not detect differences is color shades as well as they detect differences in an image brightness. Eye is less sensitive to color variation. Separating pixel color from brightness images can be split into 8 by 8 pixels blocks.
What is USB?
It is a form of serial data transmission. USB is most common type of input output port found on a computer and has a standard method for data transfer between devices. USB allows port half duplex and full duplex data transmission.
How checksum used to detect an error?
The checksum is calculated from the block of data. The calculation is done using an agreed algorithm. This algorithm must be agreed by sender and receiver. The checksum is then transmit with the block of data. At the receiving end the checksum is recalculated. The recalculated checksum is then compared to the checksum sent with the data block. If the two checksums are the same no transmission error occurred. Otherwise resend the block of data.
When a block of data to be transmit, the checksum is calculated from the block of data. This calculation is done using an algorithm agreed by the sender and receiver. The checksum is then transmit with the block of data. At the receiving end the checksum is recalculated by the computer using the block of data. The recalculated checksum is then compared to the checksum sent with the data block. If two are same no errors otherwise retransmit data.
How parity check used to detect errors?
A parity bit is added to each byte of data that is transmitted. Odd or even parity can be used. Every byte of data is checked after transmission to check if it matches the odd or even parity being used. The parity check counts the number of 1’s in the received byte to determine whether the number of 1’s is even is odd or even. An error is detected if the parity is found to be incorrect.
Write with an example, how asymmetric encryption will work?
A uses an algorithm to generate a matching pair of keys private key and public key. That will be kept on their computers. The matching pairs are mathematically linked. B uses A’s public key to encrypt the password to encrypt the password. A uses the matching private key to unlock the B’s password to decrypt it. This works because public key is used to encrypt the document and the private key is used to decrypt the password. The matching pairs are generated by the A’s computer. A cannot use public key to decrypt the message.
What is check digit?
It is the final digit included in a code. It is calculated from all the other digits in the code. They are used for barcodes on products such as ISBN.
Two advantages and disadvantages of USB.
Has become a industry standard (which mean considerable support is available)
Can support different data transmission rates (from 1.5 mbps to 5gbps)
Connections can only fit one way preventing incorrect connections being made.
Device can be automatically detected.
USB support maximum cable length of 5m
Beyond that USB hubs are needed
Slower data transfer rate
Write the difference between serial and parallel data transmission?
Serial – More reliable data transmission over longer distances.
Parallel – works well over short distances (computer circuit boards).
Serial – less risk of external interferences than with parallel due to fewer wires.
Parallel – faster rate of data transmission than serial
Serial – used to send data long distance (telephone wires)
Parallel – if the data is time sensitive parallel is the most appropriate transmission method.