Question

Television antennas often have one or more horizontalmetal bars mounted behind the receiving antenna and insulated from it, as shown in Figure 23.113. Explain qualitatively whyadding a second metal bar can make the television signal either stronger or weaker, depending on the distance between the front receiving antenna and the second bar.

Short answer

A second metal bar is added to a television antenna to increase its wavelength range

Step-by-step solution

Identification of given data

In figure represents a transmitter and receiver such the metal rods of transmitter are parallel to the metal rods of the receiver and adding a second metalbar.

Significance of electromagnetic radiation

A type of energy known as electromagnetic radiation spreads as electrical and magnetic waves that move in units of energy known as photons. Electromagnetic radiation has a spectrum with varied wavelengths and frequencies, which in turn imparts various properties.

Determining that why adding a second metal bar can make the television signal either stronger or weaker, depending on the distance between the front receiving antenna and the second bar

A second metal bar is added to a television antenna to increase its wavelength range; after the bar is added, the antenna will be able to receive a wide range of wavelengths. As a result, the UHF (Ultra High Frequency in the range of 470MHz to 960MHz) and VHF(Very High Frequency in the range of 47MHz to 250MHz) signals are received using different antennas. UHF transmissions are received using front receiving antenna, while VHF signals are typically received using metal bars.