Computer Science/IT MCQs
Topic Notes: Computer Science/IT
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
281
If the channel is \_\_, we cannot send a digital signal directly.
Answer:
Bandpass
A bandpass channel does not pass low frequencies, so a digital signal must be modulated onto a higher-frequency carrier wave to be transmitted.
282
Baud rate is:
Answer:
Twice the bandwidth of an ideal channel
According to the Nyquist theorem for a noiseless channel, the maximum baud rate is twice the bandwidth (Baud rate = 2 × Bandwidth).
283
In Ethernet, a physical address of what size, embedded in the NIC, is used?
Answer:
6-byte
Ethernet uses a 6-byte (48-bit) MAC address that is hard-coded into the Network Interface Card (NIC).
284
A band always equals:
Answer:
None of the above
In communication, a band means a frequency range, not a fixed bit or byte count.
285
Which impairment causes signal weakening due to varying speeds of frequencies?
Answer:
Distortion
Distortion occurs when different frequency components of a signal travel at different speeds through a medium, causing the signal's shape to change.
286
Propagation speed × propagation time equals:
Answer:
Distance traveled by the signal or bit
This calculation determines the distance a signal has traveled through a medium in a given amount of time.
287
Telegraph-based data communications mostly use:
Answer:
Simplex lines
Telegraphy commonly employs simplex communication for one-way data flow.
288
What does DNS stand for?
Answer:
Domain Name System
DNS translates domain names into IP addresses, enabling users to access websites easily.
289
Which IP address is an example of Class B?
Answer:
191.023.21.54
Class B IP addresses range from 128.0.0.0 to 191.255.255.255. The first octet of 191 falls within this range.
290
If a periodic signal completes one cycle in 0.001 seconds, what is its frequency?
Answer:
1 KHz
Frequency is the inverse of the period (f = 1/T). Therefore, f = 1 / 0.001s = 1000 Hz, which is 1 KHz.