The signal is aff ected by noise in a communication system _____________.

(a)

At the transmitter

(b)

At the modulator

(c)

In the channel

(d)

At the receiver

The internationally accepted frequency deviation for the purpose of FM broadcasts ____________.

(a)

75 kHz

(b)

68 kHz

(c)

80 kHz

(d)

70 kHz

The loss of strengh of a signal while propagating through a medium is known as_________.

(a)

modulation

(b)

absorption

(c)

transmission

(d)

Attenuation

Modulation is the process of superposing _______________.

(a)

low frequency audio signal on high frequency radio waves

(b)

low frequency radio signal on low frequency audio waves

(c)

high frequency radio signal on low frequency audio

(d)

high frequency audio signal on low frequency radio waves

Large band width for higher data is achieved by using ________________.

(a)

Large bandwidth for higher data is achieved

(b)

high frequency audio wave

(c)

low frequency carrier wave

(d)

low frequency audio wave

Which of the following is an example of breadcast made of communication?

(a)

Radio

(b)

Television

(c)

Mobile

(d)

both (a) & (b)

The made of propagation used by short wave broadcast services is _______________.

(a)

space wave

(b)

skywave

(c)

ground wave

(d)

both (a) & (c)

FM broad cost is preferred over AM broadcast because _______________.

(a)

It is less noisy

(b)

reproduction is of much better quality

(c)

it is more noisy

(d)

both (a) & (b)

A gound receiver in line of sight communication cannot receive direct waves due to _______________.

(a)

its low frequency

(b)

curvature of each

(c)

its high intensity

(d)

smaller antenna

In frequency modulation _____________.

(a)

the amplitude of modulated wave varies as frequency

(b)

the frequency of modulated wave varies as amplitute the frequency

(c)

the amplitude of modulated wave varies as amplitute of carrier wave

(d)

the frequency of modulated wave varies as frequency of modulating wave

In modulation process radio frequency wave is termed as ______________.

(a)

modulated wave

(b)

modulating wave

(c)

carrier wave

(d)

none

An EM wave travels in free space, only one of the following can happen to them ________________.

(a)

reflection

(b)

absorption

(c)

refraction

(d)

attenuation

The most commonly, employed modulation in satellite communication is the _____________.

(a)

amplititude modulation

(b)

FM

(c)

phase modulation

(d)

all

The radio waves can be sent from one place to another through _________ propagation.

(a)

ground wave

(b)

sky wave

(c)

space wave

(d)

all of above

When the transmitting and receiving antennas are close to the ground, the type of radio-wave propagation is_________ propagation.

(a)

ground

(b)

space

(c)

sky

(d)

ionospheric

Long distance radio communication employs _______ wave propagation.

(a)

ground

(b)

sky

(c)

space

(d)

surface

Skip distance the shortest distance between ______________.

(a)

the point of transmission and the point of reception

(b)

the uplink and the downlink station

(c)

the transmitter and the target

(d)

the receiver and the target

After the angle of refraction becomes 90^o at the ionosphere, the wave travels _________.

(a)

faster

(b)

through space

(c)

in a straight line

(d)

towards the earth

The component of the modulated wave, which has a greater frequency than that of the carrier is called __________.

(a)

upper side band

(b)

middle side band

(c)

lower side band

(d)

stoke's band

The intermediate frequency is the _________ oscillator frequency and radio frequency.

(a)

product

(b)

sum of

(c)

difference between

(d)

integral of