# Electronics and Communication Engineering - Communication Systems

26.

The rate at which information can be carried through a communication channel depends on

 A. carrier frequency B. bandwidth C. transmission loss D. transmitted power

Explanation:

Rate of information depends on bandwidth.

27.

Some types of traps used in video IF amplifier of colour TV are

 A. shunt traps B. series traps C. absorption traps D. all of the above

Explanation:

All these are used.

28.

Direct and reflected sound waves may interfere with each other.

 A. True B. False

Explanation:

PAS use moving coil microphones.

29.

A carrier is simultaneously modulated by two sine waves having modulation indices of 0.4 and 0.3. The total modulation index will be

 A. 0.1 B. 0.7 C. 0.5 D. 0.35

Explanation:

m1 = 0.4, m2 = 0.3

.

30.

A 1000 kHz carrier is simultaneously modulated with 300 Hz, 800 Hz and 2 kHz audio sine waves. Which of the following frequency is least likely to be present in the output?

 A. 1002 kHz B. 1000 kHz C. 999.2 kHz D. 998.0 kHz

Explanation:

Frequency present in the sidebands is equal to = fc ± fm, fc ± 2fm , fc ± 3fm .