Answer :

Given: -

Minimum deviation, = 30^{o}

Prism is equilateral

Formula: -

The Refractive index of the prism in terms of minimum deviation is found as,

Where, is called the minimum deviation, and A is called the angle of the prism.

Calculation: -

Hence,

Also, we know that,

So,

Conclusion: -

the velocity of light in the given prism is, 2.12 × 10^{8} m/s.

B) For emerging ray to graze along face AC,

TIR must occur on the face AC, so,

Hence, r_{AC} = 45^{o}

Also, in quadrilateral AQNR,

As, Q = R = 90^{o},

A + N = 180^{o}

As, A = 60^{o} , N = 180^{o} – 60^{o} = 120^{0}

Also,

Applying Snell’s law on face AB,

Hence for grazing incidence on face AC,

Sini_{AB}=√2× sin(15^{o}) =1.414× 0.2588=0.366

Sini_{AB}=0.366

i_{AB}=21^{o} (approx.)

Rate this question :

A. A ray of lightPhysics - Board Papers

A ray PQ incidentPhysics - Board Papers

Calculate the radPhysics - Board Papers

Draw a ray diagraPhysics - Exemplar

Between the primaPhysics - Exemplar

The phenomena invPhysics - Exemplar

A passenger in anPhysics - Exemplar