What is found in frequency modulation?
(1) Fixed frequency
(2) Fixed dimension
(3) Change in frequency and dimension
(4) Change in dimension only
Answer: (1) Frequency modulation (FM) conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant. Frequency modulation is also used in telemetry, radar, seismic prospecting and newborn EEG seizure monitoring. Frequency modulation is known as phase modulation when the carrier phase modulation is the time integral of the
FM signal. FM is widely used for broadcasting music and speech, two-way radio systems, magnetic tape recording systems and some video-transmission systems.
