A message signal of 12 kHz and peak voltage 20 V is used to modulate a carrier wave frequency 12 MHz and peak voltage 30 V. then, the modulation index is

Options

A. 0.32
B. 6.7
C. 0.67
D. 67

Answer

c

Explanation

Given, message signal peak voltage = 20 V
`:. E_(m) = 20V`
Carrier voltage `E_(c ) = 30` volt
Thus, modulation on index
`m_(a) = (E_(m))/(E_(c )) = (20)/(30) = (2)/(3) = 0.67`