+2 Physics - Communication Systems - Part 3

We are covering objective type questions on Communication Systems chapter in this series of blog posts from an examination perspective. Questions from 19 - 25 are covered in this set.

19) The ability of an Antenna to concentrate the electromagetic waves in the most desired directions is its

a) focus
b) directivity
c) frequency
d) Power

20) A microphone converts

a) sound energy into electrical energy
b) electrical energy into sound energy
c) sound energy into electromagnetic energy
d) electromagnetic energy into electrical energy

21) Frequency modulated systems are usually operated at a frequency above

a) 40 MHz
b) 20 MHz
c) 30 MHz
d) 50 MHz

22) Look at the simple Radio receiver diagram below

What should come in the place of "?"

23) Simple radio receiver circuit has

a) poor sensitivity and good selectivity
b) good sensitivity and good selectivity
c) poor sensitivity and poor sensitivity
d) good sensitivity and poor selectivity

24) The ability to select a particular wanted signal only and rejecting the unwanted signals is ------------.

25) The ability to amplify the weak signals is ---------------