Computer Science - IT MCQs
Topic Notes: Computer Science - IT
<p>MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.</p>
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
221
Which of these can impair a signal?
Answer:
All of the above
Signal quality can be degraded by attenuation (loss of strength), noise (unwanted interference), and distortion (change in waveform).
222
Which multiplexing method is used for transmitting analog signals?
Answer:
FDM
Frequency Division Multiplexing (FDM) is designed to send analog signals simultaneously.
223
Which impairment happens when outside interference disrupts a signal?
Answer:
Noise
Noise is any unwanted electrical or electromagnetic energy that degrades the quality of signals and data.
224
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.
225
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).
226
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).
227
A band always equals:
Answer:
None of the above
In communication, a band means a frequency range, not a fixed bit or byte count.
228
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.
229
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.
230
Telegraph-based data communications mostly use:
Answer:
Simplex lines
Telegraphy commonly employs simplex communication for one-way data flow.