# Calculation of carrier frequency and modulating frequency in FM wave

## For a FM signal v(t) = 15 cos ( 10* 10^{8}t + 10 sin 1220t), calculate

Carrier frequency

Modulating frequency

**Options:**

a) 159.1MHz, 194.1Hz

b) 185.5MHz, 200.15Hz

c) 350.1MHz, 200.1Hz

d) 159.1Hz, 194.1Hz

Correct Answer: a) 159.1MHz, 194.1Hz

**Explanation:**

Standard expression for FM signal is given by

v(t) = A cos ( ω_{c}t + m_{f} sin ω_{m}t)

comparing with the given equation,

Carrier frequency is given by f_{c} = 10* 10^{8}/2Π

= 159.1MHz

Modulating frequency is given by f_{m} = 1220/2Π

= 194.1Hz