In television broadcasting the total channel bandwidth required to transmit video and audio signals is:

Explanation:

Television Broadcasting Channel Bandwidth

Definition: In television broadcasting, the total channel bandwidth refers to the range of frequencies required to transmit both video and audio signals simultaneously. This bandwidth ensures that all components of the television signal, including visual content, audio content, and any additional data, are transmitted without interference or loss of quality.

Details of Bandwidth Requirements:

Television broadcasting utilizes a combination of video and audio signals that must be transmitted within a specific frequency range. The video signal requires a larger portion of the bandwidth as it contains detailed visual information, while the audio signal occupies a smaller portion for sound transmission. To prevent interference between the two signals and to maintain clarity, sufficient separation (guard bands) is also included within the allocated bandwidth.

The total channel bandwidth for standard analog television broadcasting is determined by the following components:

• Video Signal Bandwidth: The video signal typically requires a bandwidth of approximately 4.2 MHz. This bandwidth allows for the transmission of detailed visual information, such as brightness (luminance) and color (chrominance).
• Audio Signal Bandwidth: The audio signal requires a much smaller bandwidth, generally around 0.2 MHz (200 kHz). This is sufficient for transmitting high-quality monaural or stereo audio.
• Guard Band: To avoid interference between the video and audio signals, a guard band of approximately 0.15 MHz (150 kHz) is included. This ensures that the signals do not overlap and degrade each other’s quality.

Total Bandwidth Calculation:

The total channel bandwidth required for transmitting both video and audio signals can be calculated as:

Total Bandwidth = Video Signal Bandwidth + Audio Signal Bandwidth + Guard Band

Substituting the values:

Total Bandwidth = 4.2 MHz + 0.2 MHz + 0.15 MHz

Total Bandwidth = 4.575 MHz

However, in practice, the total channel bandwidth is slightly rounded up to accommodate additional factors, such as signal synchronization (horizontal and vertical sync pulses) and other engineering considerations. This results in a standard channel bandwidth of approximately 5.785 MHz for analog television broadcasting.

Correct Option Analysis:

The correct option is:

Option 2: 5.785 MHz

This option correctly represents the total channel bandwidth required to transmit both video and audio signals in analog television broadcasting. It accounts for the combined bandwidth of the video signal, audio signal, and necessary guard bands, as explained above.

Important Information

To further understand the analysis, let’s evaluate the other options:

Option 1: 2.4 MHz

This option is incorrect because 2.4 MHz is far too small to accommodate both video and audio signals in television broadcasting. The video signal alone requires a bandwidth of approximately 4.2 MHz, which exceeds this value. Therefore, this option does not meet the requirements for transmitting both signals.

Option 3: 5.578 MHz

This option is close to the correct value but is slightly lower than the standard bandwidth of 5.785 MHz. It does not account for the full guard band and other additional considerations necessary for high-quality signal transmission.

Option 4: 4.2 MHz

This option represents only the video signal bandwidth and does not include the bandwidth for the audio signal or the guard band. As a result, it is incomplete and incorrect for representing the total channel bandwidth in television broadcasting.

Conclusion:

In television broadcasting, the total channel bandwidth required to transmit both video and audio signals is approximately 5.785 MHz. This value includes the bandwidth for the video signal, the audio signal, and a guard band to prevent interference. Understanding the components and their contributions to the total bandwidth is essential for ensuring high-quality signal transmission in analog television systems.