Communications

mcqspedia.com has 9 Question/Answers about Topic Communications

In AM, the carrier is changed by a modulating signal. What parameter of the carrier is changed?

In AM, the carrier is changed by a modulating signal. What parameter of the carrier is changed?
  • A. amplitude
  • B. frequency
  • C. pulse width
  • D. phase
  • Correct Answer: Option A

The intermediate frequency in a standard AM receiver is

The intermediate frequency in a standard AM receiver is
  • A. 455 Hz.
  • B. 455 kHz.
  • C. 4.55 MHz.
  • D. none of the above
  • Correct Answer: Option B

If a 1 MHz carrier is amplitude modulated with a 5 kHz audio signal, the upper-side frequency is ________ kHz.

If a 1 MHz carrier is amplitude modulated with a 5 kHz audio signal, the upper-side frequency is ________ kHz.
  • A. 1005
  • B. 1000
  • C. 995
  • D. none of the above
  • Correct Answer: Option A

For a four-quadrant linear multiplier, what is the output voltage, given input voltages of Vx = +2 V and Vy = –10 V?

For a four-quadrant linear multiplier, what is the output voltage, given input voltages of Vx = +2 V and Vy = –10 V?
  • A. +2 V
  • B. +1 V
  • C. –2 V
  • D. –1 V
  • Correct Answer: Option C

An AM demodulator can be implemented with a linear multiplier followed by a ________ filter.

An AM demodulator can be implemented with a linear multiplier followed by a ________ filter.
  • A. low-pass
  • B. high-pass
  • C. band-pass
  • D. band-stop
  • Correct Answer: Option A

A phase-locked loop (PLL) is a feedback circuit consisting of a

A phase-locked loop (PLL) is a feedback circuit consisting of a
  • A. phase detector.
  • B. low-pass filter.
  • C. VCO.
  • D. all of the above
  • Correct Answer: Option D

Light may be propagated along a fiber-optic cable in which of the following modes?

Light may be propagated along a fiber-optic cable in which of the following modes?
  • A. multimode step index
  • B. single-mode step index
  • C. multimode graded index
  • D. all of the above
  • Correct Answer: Option D

In order for a light ray to propagate along a fiber-optic cable, what must the relationship be between the angle of incidence and the critical angle?

In order for a light ray to propagate along a fiber-optic cable, what must the relationship be between the angle of incidence and the critical angle?
  • A. θi > θc
  • B. θi < θc
  • C. θi = θc
  • D. none of the above
  • Correct Answer: Option A

A certain fiber-optic cable has the following characteristics: n1 = 1.82 and n2 = 1.73. What is the value of θc?

A certain fiber-optic cable has the following characteristics: n1 = 1.82 and n2 = 1.73. What is the value of θc?
  • A. 71.90º
  • B. 0.95º
  • C. 18.1º
  • D. 1.81º
  • Correct Answer: Option A