Electromagnetism

To determine the size of the antenna for a carrier wave of a given frequency, we use the relationship between the wavelength of the wave and the size of the antenna. The optimal length of an antenna is typically a fraction (often or ) of the wavelength of the carrier wave. Given:
- Frequency of the carrier wave, Step 1: Calculate the Wavelength The wavelength of the wave is given by: where is the speed of light ( ). Step 2: Determine the Antenna Size For an efficient antenna, the length is typically of the wavelength: Final Answer: This corresponds to option (4).