What is the full form of "FM" in radio broadcasting?

• A. Frequency Manipulation
• B. Frequency Modulation
• C. Frequency Maintenance
• D. Frequency Measure

Answer: (B)

The full form of "FM" in radio broadcasting is Frequency Modulation. This term refers to the technique used to encode information in a carrier wave by varying its frequency. In FM broadcasting, the amplitude of the carrier wave remains constant while the frequency changes according to the audio signal being transmitted. This method allows for better sound quality and reduces the effects of interference compared to other modulation types, such as AM (Amplitude Modulation). Consequently, FM is widely used for high-fidelity broadcasts of music and speech.

The other options do not accurately describe the modulation technique used in FM broadcasting, which is specifically characterized by its focus on frequency changes rather than manipulation, maintenance, or measurement.