Frequencies Used by Antenna or Cable to TV Set

Introduction:
The input used by an antenna or cable to a TV set refers to the frequencies that are transmitted through the airwaves or delivered through a cable connection. These frequencies carry the audio and video signals that allow the television to receive and display programming.

RF Frequencies:
The frequencies used by an antenna or cable to a TV set are called Radio Frequencies (RF). RF frequencies are electromagnetic wave frequencies that range from 3 kilohertz (kHz) to 300 gigahertz (GHz). They are commonly used for communication and broadcasting purposes, including television transmission.

Explanation of Options:
Let's analyze the given options to understand why option 'B' (RF) is the correct answer:

a) IF (Intermediate Frequency): Intermediate Frequency refers to a frequency that is generated during the process of signal amplification and processing in a TV receiver. It is not the input frequency used by the antenna or cable.

b) RF (Radio Frequency): RF frequencies are the correct answer. They are the actual frequencies used by an antenna or cable to transmit audio and video signals to a TV set.

c) AF (Audio Frequency): Audio Frequency refers to the range of frequencies that are audible to humans, typically between 20 Hz and 20 kHz. While audio signals are included in the transmission, the input frequencies used by the antenna or cable cover a much wider range.

d) SAP (Secondary Audio Program): SAP refers to an additional audio channel that can be provided alongside the main audio channel in a TV broadcast. It is not related to the input frequencies used by the antenna or cable.

Conclusion:
In conclusion, the input used by an antenna or cable to a TV set uses frequencies called RF (Radio Frequencies). These RF frequencies carry the audio and video signals that allow the television to receive and display programming.