# Microwave link repeaters are typically 50 km a part in TV transmission because

1.  of atmospheric attenuation

2.  of output power tube limitations

3.  microwave transmission is through surface wave which attenuates faster

4.  of earth’s curvature

4

of earth’s curvature

Explanation :
No Explanation available for this question

# The balance out the local oscillator noise at the input to the intermediate frequency or to IF amplifier is super heterodyne receivers, the microwave circuit used is

1.   balanced amplifier

2.  balanced isolator

3.  balanced phase shifter

4.   balanced microwave mixer

4

balanced microwave mixer

Explanation :
No Explanation available for this question

# If carrier modulated by a digital bit stream had one of the possible phases of 0, 90, 180 and 270 degrees, then the modulation is called

1.  BPSK

2.  OPSK

3.  QAM

4.  MSK

4

OPSK

Explanation :
No Explanation available for this question

# An FM signal with a deviation δ is passed through a mixer, and has its frequency reduced fivefold. The deviation in the output of the mixer

1.  5/δ

2.  Intermediate

3.  δ/5

4.  δ

4

δ

Explanation :
No Explanation available for this question

# Consider the following statements: 1. The bandwidth of the A.M. wave depends on the bandwidth of the modulating signal 2.  The bandwidth of the A.M. wave depends on the modulation index 3. The bandwidth of the F.M. wave, for all practical purpose depends on the modulation frequency 4. The bandwidth of the F.M. wave, for all practical purpose depends on the amplitude of the carrier. Of these statements:

1.  1 and 2 are correct

2.  1 and 3 are correct

3.  1 and 4 are correct

4.  2 and 4 are correct

4

1 and 3 are correct

Explanation :
No Explanation available for this question

# PGM systems require regenerative repeaters over long distances. The correct sequence of the operations which such a repeater performs is

1.  Timing, equalization and decision making

2.  Equalization, timing and decision making

3.  Timing, thresholding (decision) and equalization

4.  Thresholding, timing and equalization

4

Timing, equalization and decision making

Explanation :
No Explanation available for this question

# Consider the following communication systems 1. Technology 2. Radio communication 3. Microwave communication 4. Optical sequence of these systems from the point of view of increase of base band channels each of them can accommodate is

1.  2, 4, 3, 1

2.  3, 4, 1, 2

3.  1, 2, 3, 4

4.  4, 2, 1, 3

4

4, 2, 1, 3

Explanation :
No Explanation available for this question

# Which one of the following transfer functions represents the Bode plot shown in the figure

1.

2.

3.

4.

4

Explanation :
No Explanation available for this question

# The noise figure of a receiver is 1.6. Its equivalent noise temperature is

1.  464.0o K

2.  174.00 K

3.  108.75 K

4.  181.25 K

4

181.25 K

Explanation :
No Explanation available for this question

1.   A B C 1 2 3

2.   A B C 3 4 1

3.   A B C 5 4 2

4.   A B C 1 3 5

4