Question

A plane electromagnetic wave travels in vacuum along z- direction. If the frequency of the wave is 40MHz then its wavelength is

• A. 5 m
• B. 7.5 m
• C. 8.5m
• D. 10 m

Answer 1

Answer: (B)

7.5 m

Answer 2

: Wavelength,

$\lambda = \frac{c}{\upsilon} = \frac{3 \times 10^{8}ms^{- 1}}{40 \times 10^{6}s^{- 1}} = 7.5m$