Question

The wavelength difference of light waves of wave numbers $2\times {10}^6/m$ and $2.25\times {10}^6/m$ is

• A. $0.556\times {10}^{-6}m$
• B. $0.0556\times {10}^{6}m$
• C. $0.0556\times {10}^{-6}m$
• D. $0.556\times {10}^{6}m$

Answer 1

Answer: (C)

$\lambda =\frac{1}{2\times {10}^6}-\frac{1}{2.25\times {10}^6}$ $=\frac{2.25-2}{2\times 2.25\times {10}^6}$ $=\frac{0.25}{2\times 2.25\times {10}^6}$ $=0.0556\times {10}^{-6}m$