Exercise: Communication Systems

Questions for: Communication Systems

The requirements of carrier frequency are
A:
precise frequency value
B:
low frequency drift
C:
both (a) and (b)
D:
neither (a) nor (b)
Answer: C

Both should have a precise value and low drift.

📖
📝
💎
👁ïļ
The contrast control in colour TV receiver is done by
A:
chroma amplifier
B:
SAW filter
C:
video detector
D:
luminance amplifier
Answer: D

Luminance amplifier changes the luminance levels and provides contrast control.

📖
📝
💎
👁ïļ
Some advantages of optical fibre cables are
  1. small diameter
  2. Immunity to cross talk and EM interference
  3. Laser and LED modulation methods lend themselves ideally to digital operation
Which of the above are correct?
A:
1 only
B:
1 and 2
C:
1, 2, 3
D:
2, 3
Answer: C

Fibre optic cables have all these advantages.

📖
📝
💎
👁ïļ
The HV supply to a TV receiver is 25 kV and the total beam current for the three electron guns is 2000 ΞA. The power handled by IHVT is
A:
5W
B:
0.5 W
C:
50 W
D:
500 W
Answer: C

25 x 103 x 2000 x 10-6 = 50 W.

📖
📝
💎
👁ïļ
An analog signal is band limited to B Hz sampled at Nyquist rate and samples are quantized into 4 levels each with probability . The information rate is
A:
4 bits/s
B:
B bits/s
C:
4 B bits/s
D:
0.25 B bits/s
Answer: C

.

Signal should be sampled at frequency 2B Hz.

Hence, information rate = 2 (2B) = 4B bits/s.

📖
📝
💎
👁ïļ
Ad Slot (Above Pagination)
Quiz