What is the total bandwidth of a FM phone transmission that has a 5 kHz deviation and a 3 kHz modulating frequency?

To determine the total bandwidth of a frequency modulated (FM) phone transmission, you can use Carson's rule, which provides a way to estimate the bandwidth needed for an FM signal. According to Carson’s rule, the total bandwidth (BW) can be calculated using the formula:

BW = 2 * (deviation + modulating frequency)

In this scenario, the frequency deviation is given as 5 kHz, and the maximum modulating frequency is 3 kHz. Plugging these values into the formula gives:

BW = 2 * (5 kHz + 3 kHz)

BW = 2 * (8 kHz)

BW = 16 kHz

Thus, the total bandwidth required for this FM phone transmission is 16 kHz. This aligns with the choice identified as correct. Understanding this calculation is crucial, as it illustrates how both the deviation and the modulating frequency contribute to the overall bandwidth of an FM signal. This principle is widely used in communications engineering to allocate the necessary bandwidth for various transmission types.