Analog Communications Practice Test 1

1. The minimum height of antenna required for transmission in terms of ʎ is ________

^3ʎ⁄₂

^ʎ⁄₄

2ʎ

2. What is the use of a varactor diode in radio receiver?

Multiplexing

Tuning

Demodulation

Mixing

3. Singletone amplitude modulation ________

contains infinite number of frequency components

consists of only one frequency component

contains a large number of frequency components

contains no frequency components

4. Sin wave is ________

Deterministic Signal

Periodic Signal

Random Signal

Aperiodic Signal

5. AM spectrum consists of ________

Lower sideband

Carrier frequency with both upper and lower sideband

Upper sideband

Carrier frequency

6. For Amplitude Modulation, Emitter modulator ________

Operates in class B mode

Output power is high

Has a low efficiency

Operates in class C mode

7. Which devices did we use for AM Demodulation?

Ratio detector and Slope detector

PLL detector and Foster-Seeley discriminator

Only quadrature detector

Envelope detector and Square law demodulator

8. Commercial frequency deviation is ________

65 KHz

80 KHz

85 KHz

75 KHz

9. What is Amplitude Modulation?

Change in amplitude of modulating signal according to carrier signal amplitude

Change in amplitude of carrier according to modulating signal amplitude

Change in frequency of carrier according to modulating signal amplitude

Change in amplitude of carrier according to modulating signal frequency

10. In TV transmission, picture signal is ________ modulated.

SSB-SC

VSB

DSB-SC

Pulse