Question

Wave numbers of two electromagnetic radiations A and B are 100m--and 100cm-respectively. Ratio of wavelengths of A to B will
be
(A) 1:1
(B) 100:1
(C) 10:1
(D) 1:100​

Answer 1

Answer:

100:1

Explanation:

Va:Vb=1cm-1:100cm-1.

 Wavelength is  inversely proportional to wavenumber  

Therefore

wavelength A:wavelength B =100:1

Answer 2

Given:

The wave number of radiation A = 100 m⁻¹ = 1 cm⁻¹

The wave number of radiation B = 100 cm⁻¹

To Find:

The ratio of wavelengths of electromagnetic radiations A and B.

Calculation:

- Wavelength of A, λA = 1/wave number = 1/1 = 1 cm

- Wavelength of B, λB = 1/wave number = 1/100 = 0.01 cm

- Ratio of wavelengths of A and B:

λA/λB = 1/0.01

⇒ λA : λB = 100 : 1

- So, the correct answer is option (B) 100 : 1