Question

What is the purpose of a tuner in a radio?The tuner converts a direct current into a high-frequency alternating current.The tuner selects only the signal of a specific frequency and rejects the rest.The tuner detects a wide range of broadcast frequencies.The tuner converts inaudible high-frequency signals into sound waves that can be heard.

Answer 1

The tuner selects only the signal of a specific frequency and rejects the rest.

A radio receives a lot of waves, the tuner choses one of them and rejects the rest, this is possible by a principle called resonance. Resonance is a phenomenon when the amplitude of a wave is increased and this occurs when the frequency of the incident wave is close to the frequency of the receiver. A tuner is made by a capacitor and an inductor. Hence once we set a specific frequency on the tuner it resonates the wave which has a similar frequency and rejects all the other.