JEE Main202125 Feb 2021Morning ShiftPhysicsCommunication SystemActual
Given below are two statements: Statement I : A speech signal of 2 kHz is used to modulate a carrier signal of 1 MHz . The bandwidth requirement for the signal is 4 kHz . Statement II : The side band frequencies are 1002 kHz and 998 kHz . In the light of the above statements, choose the correct answer from the options given below:
Options
- AStatement I is false but Statement II is true
- BBoth Statement I and Statement II are true
- CStatement I is true but Statement II is false
- DBoth Statement I and Statement II are false
Correct answer
B. Both Statement I and Statement II are true
Step-by-step solution
f m = 2   kHz f c = 1   MHz = 1000   kHz Band width = 2 f m = 4   kHz ∴ Side frequencies will be = f c ± f m = 1000 ± 2   kHz = 998   kHz   &   1002   kHz So, statement-I & statement-II both are correct.