INTRODUCTION TO COMMUNICATION

If the output of a circuit should be a representation of less than one-half of the input signal, what class of operation should be used?
a. Class A

b. Class C

c. Class AB

d. Class AC

b

In a frequency-domain plot, the vertical axis measures the:

a. peak amplitude

b. frequency

c. phase

d. slope

a

Cosmic noise:
a. a constant radiation from the sun

b. RF noise radiated by distant stars

c. a constant radiation from the sun and RF noise radiated by distant stars

d. none of these

b

The Colpitts VFO uses:

a. a tapped inductor

b. a two-capacitor divider

c. an RC time constant

d. a piezoelectric crystal

b

A periodic voltage waveform that exhibits point (or skew) symmetry about the coordinate origin is classified as a/an:
a. even function

b. odd function

c. half-wave symmetry

d. full-wave symmetry

b

Radiowave spectrum is from ___ to ___

a. ELF, EHF

b. VF, EHF

c. VLF, EHF

d. VLF, Light frequencies

b

Television broadcasting occurs in which ranges?

a. HF

b. EHF

c. VHF

d. UHF

c

A class B amplifier conducts for how many degrees of an input sine wave?

a. 90 deg to 150 deg

b. 180 deg

c. 180 deg to 360 deg

d. 360 deg

b

Indicate the false statement. Modulation is used to:

a. reduce the bandwidth

b. separating differing transmissions

c. ensure that intelligence may be transmitted over long distances

d. allow the use of practicable antennas

a

Which of the following characterizes impulse noise?

A. it is characterized by low-amplitude peaks of long duration in the total noise spectrum

B. produced when unwanted harmonics of a signal are produced through non-linear amplification

C. it is the generation of unwanted sum and difference frequencies when two or more signals are amplified by a non-linear device

D. consists of sudden burst of irregularly shaped pulses

D