Match List-X (Medium type) with List-Y (Frequency range) and select the correct answer using the codes given below the lists:

Question

Match List-X (Medium type) with List-Y (Frequency range) and select the correct answer using the codes given below the lists:

List-X

i. Open wire

ii. Twisted pair

iii. Coaxial cable

List-Y

1. 100 KHz

2. 100 MHz

3. 5 KHz

1. A. i-3, ii-2, iii-1
2. B. i-3, ii-1, iii-2 (Correct answer)
3. C. i-2, ii-3, iii-1
4. D. i-2, ii-1, iii-3

Correct Answer

Option B — i-3, ii-1, iii-2

Detailed Solution & Explanation

The correct answer is i-3, ii-1, iii-2.

Key Points

• Open wire — 3 (5 kHz): the oldest transmission medium, an untwisted parallel pair, usable only at very low frequencies before radiation losses and crosstalk dominate.
• Twisted pair — 1 (100 kHz): twisting cancels much of the interference, extending the usable range well above open wire.
• Coaxial cable — 2 (100 MHz): the inner conductor is fully enclosed by an outer shield, confining the field and permitting far higher frequencies.
• The order of increasing capability is therefore open wire < twisted pair < coaxial cable.

Additional Information

• Optical fibre extends this progression further still, supporting bandwidths in the THz range with very low attenuation and complete immunity to electromagnetic interference.
• The physical reason for the ordering is shielding: the better the conductor is enclosed, the less energy is radiated away as frequency rises.