Question

The frequency of a light wave in a material is $2\times {10}^{14}Hz$ and wavelength is $5000\stackrel{\circ }{A}$. The refractive index of material will be :

• A. $1.50$
• B. $3.00$
• C. $1.33$
• D. $1.40$

Answer 1

Answer: (B)

$3.00$

Using,

Refractive index, $\mu =\frac{c}{v}$

Here, $c=3\times {10}^{8}m{s}^{-1}$

$v=u\lambda =2\times {10}^{14}Hz\times 5000\times {10}^{-10}m$

$=1\times {10}^{8}m{s}^{-1}$

$\therefore \mu =\frac{3\times {10}^{8}m{s}^{-1}}{1\times {10}^{8}m{s}^{-1}}=3$