Communication Systems
In case of low level amplitude modulation system, the amplifiers following the modulated stage must be

Harmonic devices
Linear devices
Non-linear devices
Class C amplifiers

ANSWER DOWNLOAD EXAMIANS APP

Communication Systems
Circular polarization

Involves critical alignment of transmitting and receiving antenna
Is useful in reducing depolarization effect on received wave
Is useful in discrimination between reception of adjacent beams
None of these

ANSWER DOWNLOAD EXAMIANS APP

Communication Systems
In case of frequency modulation, modulating voltage remains constant if the modulating frequency is lowered, then

Amplitude of distant sidebands increases
Amplitude of distant sidebands first increases, then decreases
Amplitude of distant sidebands decreases
Amplitude of distant sidebands remains constant

ANSWER DOWNLOAD EXAMIANS APP