Question

The wave number of the light emitted by a certain source is $2\times {10}^6{m}^{-1}$. The wavelength of this light is:

• A. 500 nm
• B. 500nm
• C. 200nm
• D.

Answer 1

The correct option is A 500 nm

$\overline{u}=\frac{1}{\lambda },\lambda =\frac{1}{\overline{u}}=\frac{1}{(2\times {10}^6)}=0.5\times {10}^{-5}m=5\times {10}^{-7}m=500\times {10}^{-9}m=500nm$