Question

A 25 m long antenna is mounted on an antenna tower. The height of the antenna tower is 75 m. The wavelength (in meter) of the signal transmitted by this antenna would be ______.

Options

• 200

• 400

• 100

• 300

Answer 1

A 25 m long antenna is mounted on an antenna tower. The height of the antenna tower is 75 m. The wavelength (in meter) of the signal transmitted by this antenna would be 100.

Explanation:

Given, 

The antenna's height is

H = 25 m

The antenna's transmission and reception conversion efficiency is highest when its length is 1/4 of the wavelength.

H = `lambda/4` ⇒ λ = 4H

Therefore,

 λ = 4 × 25 = 100 m