Communications - Online Test
Q1. A memory less source emits n symbols each with a probability p. The entropy of the source as a function of n
Answer : Option A
Explaination / Solution:
Q2. Bandwidth of an electronic communication system
Answer : Option C
Explaination / Solution:
A range within a band of wavelengths, frequencies, or energies; especially : a range of radio frequencies which is occupied by a modulated carrier wave, which is assigned to a service, or over which a device can operate.
Q3. A signal flow graph of a system is given below
The set of equalities that corresponds to this signal flow graph is
Answer : Option C
Explaination / Solution:
Q4. Modulation is
Answer : Option B
Explaination / Solution:
Modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted. Most radio systems uses frequency modulation (FM) or amplitude modulation (AM) to make the carrier carry the radio broadcast.
Q5.
A rectangular waveguide of internal dimensions (a = 4 cm and b = 3 cm) is to be operated in TE11 mode. The minimum operating frequency is
Answer : Option A
Explaination / Solution:
Q6. Modulation used in radio is generally
Answer : Option A
Explaination / Solution:
In electronics and telecommunications , modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted. Most radio systems usea frequency modulation (FM) or amplitude modulation (AM) to make the carrier carry the radio broadcast.
Q7. One end of a loss-less transmission line having the characteristic impedance of 75Ω and length of 1 cm is short-circuited. At 3 GHz, the input impedance at the other end of transmission line is
Answer : Option D
Explaination / Solution:
Q8. Demodulation is
Answer : Option C
Explaination / Solution:
Demodulation is extracting the original information-bearing signal from a modulated carrier wave. A demodulator is an electronic circuit (or computer program in a software-defined radio) that is used to recover the information content from the modulated carrier wave.
Q9. In the design of a single mode step index optical fibre close to upper cut-off, the single-mode operation is not preserved if
Answer : Option C
Explaination / Solution:
No Explaination.
Q10. Repeater is used for
Answer : Option B
Explaination / Solution:
In telecommunications, a repeater is an electronic device that receives a signal and retransmits it.Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction.
