Question

A signal of 100 THz frequency can be transmitted with maximum efficiency by :

• A. Coaxial cable
• B. Optical fibre
• C. Twisted pair of copper wires
• D. Water

Answer 1

The Correct Option is B

The question involves determining the most efficient medium for transmitting a signal with a frequency of 100 THz. Let's analyze each option:

1. Coaxial cable: Coaxial cables are typically used for low to medium frequency signals, up to several GHz. They are not efficient for transmitting THz frequencies, which are much higher.
2. Optical fibre: Optical fibres are designed to carry high-frequency signals over long distances with minimal loss. They operate efficiently in the THz range, especially within the infrared region, which corresponds well with a frequency of 100 THz. This makes optical fibres the best choice for high-frequency signal transmission.
3. Twisted pair of copper wires: Twisted pairs are used for lower frequency applications, typically below MHz ranges, and have significant losses at THz frequencies, making them unsuitable for this frequency.
4. Water: Water is not a medium used for deliberate signal transmission because it absorbs electromagnetic waves, particularly at high frequencies like THz, causing significant signal loss.

Conclusion: The correct answer is Optical fibre as it efficiently transmits signals in the THz frequency range due to its low attenuation and high bandwidth capabilities.