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QJEEM23Ph1c02: JEE Main 2023 Physics - Class 12 JEEM23Ph1c02 Solution: The refractive index of a transparent liquid filled in an…

The refractive index of a transparent liquid filled in an equilateral hollow prism is 2\sqrt{2} . The angle of minimum deviation for the liquid will be ___________ ∘.

Step-by-Step Verified Solution

To find the angle of minimum deviation for the liquid in the equilateral hollow prism, we can use the formula for the angle of minimum deviation based on the refractive index nn and the prism angle AA :

n=sin⁡A+δm2sin⁡A2n = \frac{\sin \frac{A + \delta_m}{2}}{\sin \frac{A}{2}}

In this case, the refractive index n=2n = \sqrt{2} , and since the prism is equilateral, the prism angle A=60∘A = 60^\circ . Now, we can substitute these values into the formula and solve for the angle of minimum deviation δm\delta_m :

2=sin⁡60∘+δm2sin⁡60∘2\sqrt{2} = \frac{\sin \frac{60^\circ + \delta_m}{2}}{\sin \frac{60^\circ}{2}}

First, let's find the sine of half the prism angle:

sin⁡60∘2=sin⁡30∘=12\sin \frac{60^\circ}{2} = \sin 30^\circ = \frac{1}{2}

Now, we can substitute this value into the formula:

2=sin⁡60∘+δm212\sqrt{2} = \frac{\sin \frac{60^\circ + \delta_m}{2}}{\frac{1}{2}}

To isolate the sine term, we multiply both sides by 12\frac{1}{2} :

22=sin⁡60∘+δm2\frac{\sqrt{2}}{2} = \sin \frac{60^\circ + \delta_m}{2}

Now, we can find the angle inside the sine function:

60∘+δm2=sin⁡−122=45∘\frac{60^\circ + \delta_m}{2} = \sin^{-1} \frac{\sqrt{2}}{2} = 45^\circ

Finally, we can solve for the angle of minimum deviation δm\delta_m :

60∘+δm=2⋅45∘60^\circ + \delta_m = 2 \cdot 45^\circ

δm=90∘−60∘=30∘\delta_m = 90^\circ - 60^\circ = 30^\circ

The angle of minimum deviation for the liquid in the equilateral hollow prism is 30∘30^\circ .

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