Which component of a radio receiver captures radio waves?

Which component of a radio receiver captures radio waves?

• A. Antenna
• B. Transmitter
• C. Modulator
• D. Mixer

Answer: (A)

This question tests how a radio receiver collects energy from the air. The component that captures radio waves is the antenna. It is designed to respond to the oscillating electric and magnetic fields of an incoming signal and converts that electromagnetic energy into an electrical signal, typically a tiny alternating current that flows into the receiver input. The efficiency and strength of this conversion depend on the antenna’s size, shape, and its impedance matching to the receiver, with antennas often sized to be related to the signal’s wavelength. The other parts have different roles: a transmitter emits the radio waves, a modulator encodes information onto the carrier at the source, and a mixer in the receiver helps shift the received signal to a lower, more workable frequency for processing. But capturing the energy from the wave itself is the antenna’s job.

This question tests how a radio receiver collects energy from the air. The component that captures radio waves is the antenna. It is designed to respond to the oscillating electric and magnetic fields of an incoming signal and converts that electromagnetic energy into an electrical signal, typically a tiny alternating current that flows into the receiver input. The efficiency and strength of this conversion depend on the antenna’s size, shape, and its impedance matching to the receiver, with antennas often sized to be related to the signal’s wavelength.

The other parts have different roles: a transmitter emits the radio waves, a modulator encodes information onto the carrier at the source, and a mixer in the receiver helps shift the received signal to a lower, more workable frequency for processing. But capturing the energy from the wave itself is the antenna’s job.