1.
What is a light pen?
Correct Answer
B. 2) Optical input device
Explanation
A light pen is an optical input device that allows users to interact with a computer by pointing at the screen. It consists of a light-sensitive tip that detects the position of the pen when it is placed on the screen. The pen emits a beam of light, and when the tip comes into contact with the screen, the light is reflected back to the pen. This reflection is then detected by sensors in the pen, allowing the computer to determine the location of the pen on the screen.
2.
Which one is the protocol?
Correct Answer
C. 3) NetBEUI
Explanation
NetBEUI is a protocol used for communication between computers on a local area network (LAN). It stands for NetBIOS Extended User Interface and is primarily used in small networks. This protocol allows computers to share files, printers, and other network resources. It is a non-routable protocol, meaning it cannot be used to communicate across different networks. The other options, such as Bus and Star, are not protocols but rather network topologies. "None of the above" and "None of these" are not valid answers as they do not provide a specific option.
3.
1KB is equal to:
Correct Answer
C. 3) 1024 bytes
Explanation
1KB is equal to 1024 bytes. This is because in digital storage, the binary system is used where each unit is a power of 2. Therefore, 1KB is equal to 2^10 bytes, which is 1024 bytes.
4.
For dial up internet connection, a computer must have:
Correct Answer
C. 3) Modem
Explanation
A dial-up internet connection requires a modem in order to establish a connection with the internet service provider. The modem converts the digital signals from the computer into analog signals that can be transmitted over a telephone line. It also converts the analog signals received from the telephone line back into digital signals that the computer can understand. Therefore, a computer must have a modem to use dial-up internet.
5.
Which of the following is not a valid memory?
Correct Answer
D. 4) NIC
6.
Which error detection method uses one's complement arithmetic?
Correct Answer
D. 4) Checksum
Explanation
Checksum is an error detection method that uses one's complement arithmetic. In this method, a sum of all the data bits is calculated and then complemented to generate the checksum. The sender appends this checksum to the data and sends it to the receiver. The receiver performs the same calculation on the received data and checks if the calculated checksum matches the received checksum. If they don't match, it indicates that an error has occurred during transmission. Therefore, the correct answer is 4) Checksum.
7.
Which error detection method consists of just one redundant bit per data unit?
Correct Answer
A. 1) Simple parity check
Explanation
The simple parity check is an error detection method that uses just one redundant bit per data unit. This method works by adding an additional bit to the data unit, called the parity bit. The value of the parity bit is chosen in a way that the total number of 1s in the data unit (including the parity bit) is either odd or even. During transmission, the sender recalculates the parity bit and compares it with the received parity bit. If they are different, an error is detected. Since only one redundant bit is used, this method is simple but can only detect errors and not correct them.
8.
In cyclic redundancy checking, what is the CRC?
Correct Answer
D. 4) The remainder
Explanation
In cyclic redundancy checking, the CRC refers to the remainder. When performing CRC, a polynomial division is carried out, where the data is divided by a predetermined divisor. The remainder obtained from this division is then appended to the data, creating the CRC. By comparing the CRC at the receiving end with the calculated CRC at the sending end, errors in the transmission can be detected. Therefore, the correct answer is 4) The remainder.
9.
The largest portion of the bandwidth for ADSL carries _______.
Correct Answer
B. 2) upstream data
Explanation
ADSL (Asymmetric Digital Subscriber Line) is a type of broadband internet connection that provides faster download speeds compared to upload speeds. The largest portion of the bandwidth for ADSL carries downstream data, which refers to the data that is being downloaded from the internet to the user's device. Therefore, the correct answer is not 2) upstream data, but rather 3) downstream data.
10.
Another name for the cable TV office is the _______.
Correct Answer
A. 1) splitter