Answer:
λ = 0.4 x 10⁻⁶ m = 400 nm
Explanation:
The relationship between frequency, wavelength and speed of an electromagnetic wave is given as follows:
[tex]c = f\lambda[/tex]
where,
c = speed of light = 3 x 10⁸ m/s
f = frequency of the light wave = 7.5 x 10¹⁴ Hz
λ = wavelength of the light = ?
Therefore,
[tex]3\ x\ 10^8\ m/s = (7.5\ x\ 10^{14}\ Hz)\lambda\\\\\lambda = \frac{3\ x\ 10^8\ m/s}{7.5\ x\ 10^{14}\ Hz}[/tex]
λ = 0.4 x 10⁻⁶ m = 400 nm