MCQ
Two light rays initially in same phase travel through two media of equal length $L$ having refractive index $m _1$ and $m_2\left(m_1 > m_2\right)$ as shown in figure. If the wave length of light rays in air is $1$ , the phase difference of the emerging rays is given by
  • A
    $\frac{L \mu_1}{\lambda \mu_2}$
  • B
    $\frac{\left(\mu_1-\mu_2\right) L}{2 \pi \lambda}$
  • $\frac{2 \pi\left(\mu_1-\mu_2\right) L}{\lambda}$
  • D
    $0$

Answer

Correct option: C.
$\frac{2 \pi\left(\mu_1-\mu_2\right) L}{\lambda}$
c
(c)

Path difference between the emerging rays $=\mu_1 L -\mu_2 L$

$\frac{\phi}{2 \pi}=\frac{\left(\mu_1-\mu_2\right) L}{\lambda}$

$\therefore \phi=\frac{\left(\mu_1-\mu_2\right) L}{\lambda}$

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