JEE Main20231 Feb 2023Evening ShiftPhysicsCommunication SystemActual
In an amplitude modulation, a modulating signal having amplitude of X V is superimposed with a carrier signal of amplitude Y V in first case. Then, in second case, the same modulating signal is superimposed with different carrier signal of amplitude 2 Y V . The ratio of modulation index in the two case respectively wil be :
Options
- A1   :   2
- B1   :   1
- C2   :   1
- D4   :   1
Correct answer
C. 2   :   1
Step-by-step solution
Modulating index is stated as μ = A m A c , where, A m = amplitude of modulating signal and A c = amplitude of carrier signal. Now, for first case, μ 1 = X Y For second case, μ 2 = X 2 Y Thus, the ratio of μ 1 μ 2 = X Y X 2 Y = 2 1 ⇒ μ 1 : μ 2 = 2 : 1