Question

If a source is transmitting electromagnetic waves of frequency $ 8.2\times {{10}^{6}}Hz $ , the wavelength of electromagnetic wave transmitted from the source is:

• A. 18.8m
• B. 36.5m
• C. 42.8m
• D. 58m

Answer 1

Answer: (B)

Electromagnetic waves travel with speed of light.
The relation between frequency $ (f) $ , speed $(c)$ and wavelength $ (\lambda ) $ is $ f=\frac{c}{\lambda } $
Given, $ f=8.2\times {{10}^{6}}Hz,$
$c=3\times {{10}^{8}}m/s $
$ \therefore $ $ \lambda =\frac{3\times {{10}^{8}}}{8.2\times {{10}^{6}}}=36.5\,m $