# Power Calculation MCQ’s

This set of Analog Communication Multiple Choice Questions & Answers (MCQs) focuses on “Power Calculation”.

1. Maximum Amplitude of an amplitude modulated 10V and minimum amplitude is 5V. Find its modulation index?

a) 0.65

b) 0.9

c) 0.33

d) 1

2. 24 channels, each band limited to 3.4 KHz, are to be time division multiplexed. Find the bandwidth required for 128 quantization level? (Given that sampling frequency is 8 KHz)

a) 2436 KHz

b) 1002 KHz

c) 1536 KHz

d) 1337 KHz

3. If peak voltage of a carrier wave is 10V, what is the peak voltage of modulating signal if modulation index is 50%?

a) 10V

b) 20V

c) 8V

d) 5V

4. Sampling frequency of a signal is 6 KHz and is quantized using 7 bit quantizer. Find its bit rate?

a) 48kbPs

b) 64kbPs

c) 16kbPs

d) 8kbPs

5. For 50% modulation, power in each sideband is ________ of that of carrier.

a) 10%

b) 4.32%

c) 5%

d) 6.25%

6. If each element of signal occupies 70ms, what will its speed?

a) 11.23 bauds

b) 14.28 bauds

c) 17.39 bauds

d) 13.33 bauds

7. Calculate power in each sideband, if power of carrier wave is 96W and there is 40% modulation in amplitude modulated signal?

a) 11.84W

b) 6.84W

c) 3.84W

d) 15.84W

8. For 100% modulation, total power is ________

a) 1.5P_{c}

b) 2P_{c}

c) 3.75P_{c}

d) 1.25P_{c}

9. Power of carrier wave is 300W and modulation index is 0.75. Find its total power?

a) 465W

b) 384W

c) 323W

d) 502W

10. Find the power saving for DSB-SC wave with 100% modulation?

a) 66%

b) 86%

c) 50%

d) 33%

11. If power transmitted is 45kW, field at a distance of 23km will be ________

a) 0.02

b) 0.75

c) 0.05

d) 0.03

12. If a wave is modulated by two waves. One of them has modulation index equal to 0.75 and other has 0.2, the total modulation index will be ________

a) 0.67

b) 0.58

c) 0.77

d) 0.35

13. Find the number of pulses, if the number of level is 128 in PCM?

a) 3

b) 6

c) 4

d) 7