Question

In A.M. modulation, the frequency of carrier wave is set by:
A. R.F. amplifier
B. Antenna
C. Buffer amplifier
D. R.F. oscillator

Answer 1

Hint: To find which one of the following is used for amplitude modulation, we will check for the types of electronic oscillator. There are three types of electronic oscillator with different frequency ranges. We will check for the one whose frequency suits the carrier wave. The frequency for transmitting messages in amplitude modulation is around 100KHz to 100GHz . R.F. modulation also has the frequency range of 100KHz to 100GHz. Hence from the different electronic oscillators we will conclude that R.F. an oscillator will be used for the amplitude modulation of the carrier wave.

Complete step by step answer:
Amplitude modulation is a technique that transmits messages with the help of radio carrier waves. The amplitude variation of the carrier wave depends on the message signal. The oscillator which produces signals having a range of two is known as the R.F. oscillator. The high-powered alternating output is generally produced by R.F. oscillator. R.F. An oscillator is formed from the number of resistors, capacitors and inductors.

In A.M. modulation, the frequency of the carrier wave is set by R.F. oscillator.

So, the correct answer is “Option D”.

Note:
The oscillators generally can be categorised into three categories. The one which produces frequency below 20Hz is a low frequency oscillator. The one which produces frequency in the range 16Hz to 20Hz is the audio oscillator and the one which produces radio frequency is the R.F. oscillator within the range 100KHz to 100GHz.