Question

An FM transmitter without signal input is called:

• A. Modulation
• B. Frequency deviation
• C. Frequency modulation
• D. None of the above

Hint:

Frequency modulation involves changing the frequency of a carrier wave in response to an input signal, but without a signal, no modulation occurs.

Answer 1

The Correct Option is D

The question asks: "An FM transmitter without signal input is called:". We are provided with the following options:

• Modulation
• Frequency deviation
• Frequency modulation
• None of the above

To determine the correct answer, we need to understand the concepts involved:

• Modulation: This is the process of varying one or more properties of a periodic waveform, typically a high-frequency carrier signal, with a modulating signal that contains the information to be transmitted. In the context of FM (Frequency Modulation), modulation involves changing the frequency of the carrier wave in accordance with the signal.
• Frequency deviation: This refers to the maximum change in instantaneous frequency of the signal from the carrier frequency in FM transmission. It's a measure used in frequency modulation, but it doesn't refer to the operation of an FM transmitter without input.
• Frequency modulation: This is a modulation technique where the frequency of the carrier wave is varied in accordance with the message signal. However, without any signal input, this process cannot occur.

Considering these explanations, an FM transmitter without a signal input essentially emits just the carrier frequency without any modulation taking place, because there's no information signal to alter the carrier's frequency:

• Thus, none of the terms directly define an FM transmitter without a signal input. Hence, the correct answer is:

Correct Answer: None of the above