Explore topic-wise MCQs in Digital Communications.

This section includes 19 Mcqs, each offering curated multiple-choice questions to sharpen your Digital Communications knowledge and support exam preparation. Choose a topic below to get started.

1.

Which has same probability of error?

A. BPSK and QPSK
B. BPSK and ASK
C. BPSK and PAM
D. BPSK and QAM
Answer» D. BPSK and QAM
2.

QAM uses ______ as the dimensions.

A. In phase
B. Quadrature
C. In phase & Quadrature
D. None of the mentioned
Answer» D. None of the mentioned
3.

Which is called as on-off keying?

A. Amplitude shift keying
B. Uni-polar PAM
C. Amplitude shift keying & Uni-polar PAM
D. None of the mentioned
Answer» D. None of the mentioned
4.

Matched filter is a _____ technique.

A. Modulation
B. Demodulation
C. Modulation & Demodulation
D. None of the mentioned
Answer» C. Modulation & Demodulation
5.

Simulation is used to determine

A. Bit error rate
B. Symbol error rate
C. Bit error
D. Symbol error
Answer» B. Symbol error rate
6.

If we correlate the received signal with both orthogonal function the inner product will be

A. In phase
B. Quadrature
C. In phase and quadrature
D. Unity
Answer» D. Unity
7.

MATCHED_FILTER_IS_A_______TECHNIQUE.?$

A. Modulation
B. Demodulation
C. Modulation & Demodulation
D. None of the mentioned
Answer» C. Modulation & Demodulation
8.

SIMULATION_IS_USED_TO_DETERMINE?$

A. Bit error rate
B. Symbol error rate
C. Bit error
D. Symbol error
Answer» B. Symbol error rate
9.

QAM uses ______ as the dimensions.$

A. In phase
B. Quadrature
C. In phase & Quadrature
D. None of the mentioned
Answer» D. None of the mentioned
10.

Which is called as on-off keying?$

A. Amplitude shift keying
B. Uni-polar PAM
C. Amplitude shift keying & Uni-polar PAM
D. None of the mentioned
Answer» D. None of the mentioned
11.

Which system uses QAM?

A. Digital microwave relay
B. Dial up modem
C. Digital microwave relay & Dial up modem
D. None of the mentioned
Answer» D. None of the mentioned
12.

If we correlate the received signal with both orthogonal function the inner product will b?

A. In phase
B. Quadrature
C. In phase and quadrature
D. Unity
Answer» D. Unity
13.

If we correlate the received signal with any one of the two orthogonal function, the obtained inner product will be

A. In phase
B. Quadrature
C. Zero
D. Cannot be determined
Answer» D. Cannot be determined
14.

Every frequency has ____ orthogonal functions.

A. One
B. Two
C. Four
D. Six
Answer» C. Four
15.

In non coherent reception _____ is measured.

A. Phase
B. Energy
C. Power
D. None of the mentioned
Answer» C. Power
16.

FSK reception uses

A. Correlation receiver
B. PLL
C. Correlation receiver & PLL
D. None of the mentioned
Answer» D. None of the mentioned
17.

FSK reception is

A. Phase Coherent
B. Phase non coherent
C. Phase Coherent & non coherent
D. None of the mentioned
Answer» D. None of the mentioned
18.

Which FSK has no phase discontinuity?

A. Continuous FSK
B. Discrete FSK
C. Uniform FSK
D. None of the mentioned
Answer» B. Discrete FSK
19.

Average energy per bit is given by

A. average energy symbol/log2 M
B. average energy symbol * log2 M
C. log2 M/ Average energy symbol
D. none of the mentioned
Answer» B. average energy symbol * log2 M