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A ray of light incident in air strikes a rectangular glass block of refractive index 1.50, at an angle of incidence of 45°. Calculate the angle of refraction in the glass.​

Answer :

Answer:

Approximately [tex]28^{\circ}[/tex].

Explanation:

The refractive index of the air [tex]n_{\text{air}}[/tex] is approximately [tex]1.00[/tex].

Let [tex]n_\text{glass}[/tex] denote the refractive index of the glass block, and let [tex]\theta _{\text{glass}}[/tex] denote the angle of refraction in the glass. Let [tex]\theta_\text{air}[/tex] denote the angle at which the light enters the glass block from the air.

By Snell's Law:

[tex]n_{\text{glass}} \, \sin(\theta_{\text{glass}}) = n_{\text{air}} \, \sin(\theta_{\text{air}})[/tex].

Rearrange the Snell's Law equation to obtain:

[tex]\begin{aligned} \sin(\theta_{\text{glass}}) &= \frac{n_{\text{air}} \, \sin(\theta_{\text{air}})}{n_{\text{glass}}} \\ &= \frac{(1.00)\, (\sin(45^{\circ}))}{1.50} \\ &\approx 0.471\end{aligned}[/tex].

Hence:

[tex]\begin{aligned} \theta_{\text{glass}} &= \arcsin (0.471) \approx 28^{\circ}\end{aligned}[/tex].

In other words, the angle of refraction in the glass would be approximately [tex]28^{\circ}[/tex].

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