The wavelength of ultraviolet radiation is 400nm. If the speed of light in air is 3 x 108ms-1, then the frequency of the ultraviolet radiation is
1.3 x 1015Hz
7.5 x 105Hz
1.2 x 1011Hz
7.5 x 1014Hz
Correct answer is D
F = \(\frac{V}{\lambda}\)
= \(\frac{3 \times 10^8}{400 \times 10^{-9}}\)
= 75 x 1015Hz
= 7.5 x 10^14 Hz