Concept:Modulation techniques differ in bandwidth, power requirements, and the mathematical relationship between phase and frequency.
Explanation:Statement 1 is correct. In Amplitude Modulation, the modulated signal produces an upper and lower sideband, each with a bandwidth equal to the modulating signal frequency. Therefore, the total bandwidth is twice the modulating frequency.
Statement 2 is incorrect. Frequency Modulation requires more power than AM for the same coverage area because it uses a wider bandwidth and higher transmission power to achieve better noise immunity and signal clarity.
Statement 3 is correct. Phase Modulation becomes equivalent to Frequency Modulation when the modulating signal is integrated before phase modulation. This works because frequency is the derivative of phase; integrating the signal before phase modulation changes the output to frequency modulation.
Answer:C. 1 and 3 only