Communication Systems - ECE Questions and Answers

Whatsapp
Facebook
Copy
Copy Text
Copy
Copy URL

In EM waves, polarization

is always vertical in an isotropic medium

is caused by reflection

is due to transverse nature of waves

results from longitudinal nature of waves

Whatsapp
Facebook
Copy
Copy Text
Copy
Copy URL

The maximum power output of a standard A earth station over the total band allocated to satellite communication is about

0.5 kW

8 kW

20 kW

50 kW

Whatsapp
Facebook
Copy
Copy Text
Copy
Copy URL

PAM stands for

Pulse Analogue Modulation

Phase Analogue Modulation

Pulse Amplitude Modulation

Phase Amplitude Modulation

Whatsapp
Facebook
Copy
Copy Text
Copy
Copy URL

The characteristic impedance of a twin wire feeder used for TV signals is about

1000 ohm

500 ohm

300 ohm

100 ohm

Whatsapp
Facebook
Copy
Copy Text
Copy
Copy URL

In a FM receiver, amplitude limiter

amplifiers low frequency signals

reduces the amplitude of signals

eliminates any change in amplitude of received FM signals

none of the above

Whatsapp
Facebook
Copy
Copy Text
Copy
Copy URL

A buffer amplifier is

a double-tuned amplifier

a high gain D.C. amplifier

a cathode follower stage

none of the above

Whatsapp
Facebook
Copy
Copy Text
Copy
Copy URL

Leak type bias is used in plate modulated class C amplifier to

increase the bandwidth

prevent over modulation

prevent excessive grid current

prevent tuned circuit damping

Whatsapp
Facebook
Copy
Copy Text
Copy
Copy URL

The direction of rotation of a CD is

clockwise

anticlockwise

clockwise or anticlockwise depending on frequency of data stored

mostly anticlockwise but some times clockwise

Whatsapp
Facebook
Copy
Copy Text
Copy
Copy URL

One of the advantages of base modulation over collector modulation of a transistor class C amplifier is

improved efficiency

better linearity

high power output per transistor

the lower modulating power requirement