Amplitude modulated wave is represented by V AM = 10 1 + 0 . 4 cos 2 π × 10 4 t cos 2 π × 10 7 t . The total bandwidth of the amplitude modulated wave is

Step-by-step solution

Expression for modulation is given by, s t = A c 1 + μ cos 2 π f m t cos 2 π f c t , where f m and f c are the frequency of the modulating signal and the carrier signal respectively. Comparing it with the given expression in question, we get, f m = 10 4   Hz Now, Bandwidth = 2 f m = 20   kHz