Questions and answers for exam Preparation

MCQs

Total Questions : 155 | Page 7 of 16 pages

Question 61. Brewster angle is the angle at which

No reflection occurs at the first medium
Reflection coefficient is zero
The wave gets refracted in the direction of source
Both a and b
Both a and c

Discuss Question

Answer: Option D. -> Both a and b
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 62. When a wave falls on a perfect conductor

Wave is partially reflected and partially transmitted
All incident energy is reflected back without loss of energy
Part of energy gets absorbed
Both a and c

Discuss Question

Answer: Option B. -> All incident energy is reflected back without loss of energy
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 63. Fading is caused due to
1. Multi path propagation
2. Obstacles
3. Frequency variations at the source
4. Variation in amplitude and phase at receiver

1 and 2 are correct
1, 2 and 4 are correct
2 and 3 are correct
All are correct

Discuss Question

Answer: Option B. -> 1, 2 and 4 are correct
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 64. Coherence time refers to

Time required to attain a call with the busy base station
Time required for synchronization between the transmitter and the receiver
Minimum time for change in magnitude and phase of the channel
None of the above

Discuss Question

Answer: Option C. -> Minimum time for change in magnitude and phase of the channel
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 65. Fading due to shadowing is

Fading due to large obstructions
Large coherence time of the channel as compared to the delay constraints
Small coherence time of the channel as compared to the delay constraints
Both a and b
Both a and c

Discuss Question

Answer: Option D. -> Both a and b
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 66. Deep fade is
1. Strong destructive interference
2. Drop in signal to noise ratio
3. Temporary failure of message transfer

1 and 2 are correct
1 and 3 are correct
2 and 3 are correct
All are correct

Discuss Question

Answer: Option D. -> All are correct
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 67. Doppler spread refers to

Signal fading due to Doppler shift in the channel
Temporary failure of message transfer
Large coherence time of the channel as compared to the delay constraints
All of the above

Discuss Question

Answer: Option A. -> Signal fading due to Doppler shift in the channel
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 68. According to Friis free space equation
1. Received power falls with square of the distance between the transmitter and receiver
2. Increases with square of the distance between the transmitter and receiver
3. Received power increases with gains of transmitting and receiving antennas

1 and 2 are correct
1 and 3 are correct
All the three are correct
2 and 3 are correct

Discuss Question

Answer: Option C. -> All the three are correct
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 69. Friis free space equation
1. Is an expression for noise power
2. Is a function of transmitting and receiving antenna gain
3. Depends upon the distance between transmitting and receiving antenna

1 and 2 are correct
1 and 3 are correct
2 and 3 are correct
All are correct

Discuss Question

Answer: Option C. -> 2 and 3 are correct
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 70. The free space model of propagation refers to
1. Unobstructed line of sight between the transmitter and receiver
2. Satellite communication systems and Microwave line of sight radio links
3. Propagation along the ground surface