Question

The minimum height of antenna required for transmission in terms of ʎ is ________

(a) ^3ʎ⁄2

(b) ^ʎ⁄4

(c) 2ʎ

(d) ʎ

This question was addressed to me in an interview for internship.

I need to ask this question from Source of Information in chapter Elements of Communication System of Analog Communications

Answer 1

Correct choice is (b) ^ʎ⁄4

The best explanation: For effective transmission, height of antenna should be one-forth of ʎ.

(H = ^ʎ⁄4 where ʎ = ^c⁄f). The reason for maintaining antenna height to ʎ/4 is for matching impedance. It means that the antenna is atleast 1/4^th above ground level.