Question 49
Electromagnetic SpectrumThe wavelength of ultraviolet radiation is 400 nm. If the speed of light in air is 3 × 108 m s−1, then the frequency of the ultraviolet radiation is
- A.1.3 × 1015 Hz
- B.7.5 × 105 Hz
- C.1.2 × 1011 Hz
- D.7.5 × 1014 Hz
Show the answer and explanation
Answer: D (7.5 × 1014 Hz)
Explanation
f = c/λ = 3 × 108 ÷ (400 × 10−9) = 7.5 × 1014 Hz.