Spectrum — Question 1

As we know,

Speed of light (c) = Frequency (f) x Wavelength (λ)

Given,

λ = 550 nm

= 550 × 10^-9 m

= 0.55 x 10^-6 m

C = 3 x 10⁸ m s^-1

Substituting the values in the formula, we get,

$3 \times 10^8 = \text {f} \times 0.55 × 10^{-6} \\[0.5em] \text {f} = \dfrac {3 \times 10^8 }{0.55 × 10^{-6}} \\[0.5em] \Rightarrow \text {f} = 5.45 \times 10^{14} \text {Hz} \\[0.5em]$

Hence, we get,

Frequency = 5.4 × 10¹⁴ Hz