A digital signal –

Modern communication systems use –

The audio signal –

The process of changing some characteristic of a carrier wave in accordance with the intensity of the signal is called –

If a carrier wave of 1000 kHz is used to carry the signal, the length of transmitting antenna will be equal to –

The types of modulation which are possible, are –

In amplitude modulation –

Modulation factor determines –

Degree of modulation –

The AM wave contains three frequencies, viz.:

In AM wave, carrier power is given by –

Fraction of total power carried by side bands is given by –

Which of the following is/are the limitations of amplitude modulation?

What is the frequency above which radiation of electrical energy is parctical ?

What type of modulation is employed in India for radio transmission ?

For a carrier frequency of 100 kHz and a modulating frequency of 5 kHz what is the width of AM transmission -

Which one of the following subsystems is used for satellite's orbit position and altitude ?

Intelsat satellite works as a:

Intelsat satellite is used for :

A geo-synchronous satellite is :

The frequency band used for rader relaysystems and television -

Fading applies to :

When microwave signals follow the curvature of earth, this is known as :

In which of the region of earth's atmosphere temperature decreases with height ?

Polarization in electromagnetic wave is caused by -

An 'antenna' is -

The characteristic impedance of a lossless transmission line is given by -

The Q of a resonant transmission line is -

The distance between consecutive maxima and minima is given by -

Through which mode of propagation, the radiowaves can be sent from one place to another -

The frequencies of electromagnetic waves employed in space communication vary over a range of -

The wavelength of electromagnetic waves employed for space communication lie in the range of -

The radiowaves of frequency 300 MHz to 3000 MHz belongs to -

The maximum range of ground or surface wave propagation depends on -

 In which frequencies range space waves are normally propagated -

For television broadcasting, the frequency employed is normally -

The sound waves after being converted into electrical waves are not transmitted as such because -

The process of superimposing signal frequency (i.e. audio wave) on the carrier wave is known as -

In an amplitude modulated wave for audiofrequency of 500 cycles/second, the appropriate carrier frequency will be -

Radio waves of constant amplitude can be generated with -

Range of frequencies allotted for commercial FM radio broadcast is -

Intelset satellite works as a -

The space waves which are affected seriously by atmospheric conditions are -

A sky wave with a frequency 55 MHz is incident on D-region of earth's atmosphere at 45°. The angle of refraction is (electron density for D-region is 400 electron/c.c.) - 

Which of the following is not transducer ?