# Frequency Modulation

1. What type of signal is represented by the code 15A3?

2. Briefly explain the difference between phase and frequency modulation.

3. A 15 mV sinusoid with input frequency 450 Hz is applied to an FM generator with k = 1000 Hz/20 mV. Find the positive frequency deviation.

4. An FM signal is given by e = 40 sin (2Æ'Ã? ~106t + 10 sin 600 Æ'Ã?t). What is the carrier frequency? What is the modulation index?

5. An FM signal 400 sin (2Æ'Ã? ~108t + 8 sin 200 Æ'Ã?t) is applied to a 100 Æ'¶ antenna. What is the transmitted power?

6. The maximum deviation in broadcast FM is 75 kHz. Suppose that a commercial FM system has modulating frequencies 40 Hz to 20 kHz. What is the permissible range for the modulation index?

7. What is the sensitivity of an FM receiver with a 100 mV quieting voltage and a voltage gain of 50,000?

8. Consider phase locked-loop FM demodulation. What is the meaning of the term hold-in range?

9. Name the 3 possible states of operation for a phase locked-loop.

10. An FM station transmits at 96.5 MHz. Find the local oscillator frequency and image frequency if the receiver has a 10.7 MHz IF.

https://brainmass.com/engineering/power-engineering/379680

#### Solution Summary

This posting contains the solution to the given problems.