An amplitude-modulated wave is represented by, C m ( t ) = 10 ( 1 + 0 . 2 cos 12560 t ) sin 111 × 10 4 t V . The modulating frequency in kHz will be

Step-by-step solution

The function of the amplitude-modulated wave is represented by, C m = A C 1 + A m A C sin 2 π f m t , now compare it from the given equation, C m ( t ) = 10 ( 1 + 0 . 2 cos 12560 t ) sin 111 × 10 4 t   V ⇒ 2 π f m = 12560   s - 1 ⇒ f m = 2000   Hz = 2   kHz .