Question

The Phenomenon of resonance is used in receiving the radio and television programs
(A) TRUE
(B) FALSE
(C) NEITHER
(D) EITHER

Answer 1

Hint: To explain the phenomenon of resonance and how it affects the tuning mechanism of a TV or a radio set. The capacitance of a capacitor in the tuning of the circuit is changed accordingly such that the resonant frequency of the circuit will be almost equal to the frequency of the radio signal to be received and when this happens the amplitude of the current becomes maximum in the receiving circuit. Concerning this, we can choose from the options given.


Complete answer:
Resonance can be defined as a vivid case of forced vibration in which the natural frequency of vibration of the body is equal to the impressed frequency of the external periodic force and the amplitude of forced vibration is very high. The capacitance of a capacitor in the tuning of the circuit changes according to the resonant frequency of the circuit where it becomes equal to the frequency of the received radio signal when this happens the amplitude of the current becomes maximum in the circuit.
At the resonant frequency, the current amplitude is maximum ${I_m} = \dfrac{{V_m^{}}}{R}$. Resonant Circuits have a variety of applications. For example in the mechanism of a radio or TV set. The antennas of a radio receive signals from mostly broadcasting stations. The signals picked up in the antennas behave like a source in the tuning circuit of the radio station while tuning the radio. In tuning, we differentiate the capacitance of a capacitor such that the resonant frequency of the circuit becomes very much closer to the frequency of the radio signal that is being received.
When this process happens, the amplitude of the current following the frequency of the signal of the particular radio station in the circuit is maximum. The circuit is resonant when you have a bunch of different frequencies that are driving a resonant system, the response is only strong for that kind of frequency which is near to the natural frequency of the resonant oscillator. The frequency-dependent amplification is done through the resonance circuit for the desired frequency.
Hence answer is Option A) True.

Note: Antenna resonance and bandwidth are the two properties for antennas that are closely related. Whether the radio antenna is used for broadcasting, TV and radio reception, WLAN, cellular telecommunications, PMR, amateur radio, etc, the performance of the antenna is imminent. In this, the antenna resonant frequency and the antenna bandwidth are of very much importance.