Question

An antenna is mounted on a 400 m all building. What will be the wavelength of signal that can be radiated effectively by the transmission tower upto a range of 44 km?

• A. $75.6\text{m}$
• B. $302\text{m}$
• C. $37.8\text{m}$
• D. $605\text{m}$

Answer 1

Answer: (D)

Given Data:

Height of Building, $d=400m$

Range of transmission, $R=44km=44000m$

Solution:

From relation between height of antenna and range of transmission, $d^2=2Rh$

height of the antenna, $h=\frac{d^2}{2R}⟹h=\frac{{400}^2}{2\times 44000}\sim 151m$
Wavelength of signal, $\lambda =4h⟹\lambda =4\times 151m=604m$