An amplitude moduated signal consists of a message singnal of frequency 1 KHz and peak voltage of 5 V , moduating a carrier frequency of 1 MHz and peak voltage of 15 V . The correct description of this singnal is

Options

A. `5[1+3 sin(2 pi 10^6 t)] sin (2pi 10^3 t)`
B. `15[1+1/3 sin(2pi 10^3 t)] sin(2pi 10^6t)`
C. `[5+ 15 sin (2 pi 10^3 t)] sin(2pi 10^6t)`
D. `[15 +5 sin (2 pi10^6t)] sin(2pi10^3t)`

Answer

B

Explanation

Answer(2) `C_m(t) = A_c [ 1 + A_m/A_c sinomega_mt] sinomega_m t`
`A_c = 15, A_m = 5, omega_m = 2pif_m = 2pi xx 10^+3`.
`omega_c = 2 pif_c = 2pi(10^6)` .
`therefore C_m(t) = 15[ 1+ 5/15 sin 2pi (10^3t)] sin [2pi(10^6t`)].
= `15[ 1+ 1/3 sin 2pi (10^3t)] sin [2pi(10^6t`)]`.