Question

The value of Planck’s constant is 6.63 × 10⁻³⁴ Js. The speed
of light is 3 × 10¹⁷ nm s⁻¹. Which value is closest to the
wavelength in nanometer of a quantum of light with
frequency of 6 × 10¹⁵ s⁻¹? [2013]
(a) 25 (b) 50 (c) 75 (d) 10

Answer 1

The value closest to the  wavelength in nanometer is 50.

Explanation:

Given data:

Speed of light = 3×10¹⁷ nm/s

Frequency = 6×10¹⁵ s⁻¹

Wavelength = ?

Solution:

Formula:

Speed of light = wavelength × frequency

Now we will put the values in formula.

3×10¹⁷ nm/s = wavelength ×  6×10¹⁵ s⁻¹

wavelength =  3×10¹⁷ nm/s / 6×10¹⁵ s⁻¹

wavelength = 50 nm