IndiaBIX

Electronics and Communication Engineering - Communication Systems

Exercise : Communication Systems - Section 8
36.

Assertion (A): For satellites and space probes, PRF of a radar is pretty low.

Reason (R): PRF of a radar depends on the range of a radar.

Both A and R are correct and R is correct explanation of A
Both A and R are correct but R is not correct explanation of A
A is correct but R is wrong
A is wrong but R is correct
Answer: Option
Explanation:

PRF means Pulse Repetition Frequency.

37.
An S/N ratio of 3 expressed in db is
4.8 dB
2.4 dB
0.48 dB
0.24 dB
Answer: Option
Explanation:

10 log10 3 = 4.8 .

38.
The material used for the magnet of moving coil cone type loudspeaker is
steel alloy
soft iron
hard steel
Alnico
Answer: Option
Explanation:

Alnico produces a strong magnetic field.

39.
CCIR system B employs
625 lines
625 lines with 2 : 1 interlace
625 lines with 4 : 1 interlace
500 lines with 2 : 1 interlace
Answer: Option
Explanation:

625 lines divided into odd and even fields, i.e., 2 : 1 interlace.

40.
The power to the base unit of a cordless telephone is supplied by
battery
AC mains
both battery and AC mains
either battery or AC mains
Answer: Option
Explanation:

Base unit is fed from ac mains and portable unit from battery.

Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers