Question

The wavelength of light in vacuum is $5000\mathring{A}$. When it travels normally through diamond of thickness $1.0mm$ find the number of waves of light in $1.0mm$ of diamond. (Refractive index of diamond $=2.417$)

• A. $4834$ waves
• B. $5834$ waves
• C. $4384$ waves
• D. $6834$ waves

Answer 1

The correct option is A $4834$ waves

Wavelength of light in vacuum$\left(\lambda \right)$= $5000A^{\circ }$

Thickness (t) = 1.0 mm

Number of waves of light is given by the formula

$\text{n =}\frac{\text{distance travelled}}{\text{wavelength}}=\frac{\mu d}{\lambda }$

Substituting the values,

$\text{n =}\frac{2.417\times 1\times {10}^{-3}}{5000\times {10}^{-10}}$

$\text{n = 4834 waves}$

The number of waves of light in 1.0 mm of diamond is 4834 waves.