Numerical Problems Based on Total Internal Reflection and Critical Angle for Class 12 Physics
Here we are providing numerical problems based on topic total internal reflection and critical angle for class 12 physics.
Q.1. Calculate the critical angle for glass-air surface, if a ray of light which is incident in air on the glass surface is deviated through 15°, when angle of incidence is 45°.
Q.2. Find the value of critical angle for a material of refractive index √3.
Q.3. The critical angle of incidence in a glass slab placed in air is 45°. What will be the critical angle when it is immersed in water of refractive index 1.33?
Q.4. For a situation shown in Figure, find the maximum angle ‘i’ for which the light suffers total internal reflection at the vertical surface.
Q.5. The refractive index of water is 4/3. Obtain the value of the semi vertical angle of the cone within which the entire outside view would be confined for a fish under water. Draw an appropriate ray diagram.
Q.6. Calculate the speed of light in a medium, whose critical angle is 30°.
Q.7. In the following ray diagram, calculate the speed of light in the liquid of unknown refractive index.
Q.8. A point source of light S is placed at the bottom of a vessel containing a liquid of refractive index 5/3. A person is viewing the source from above the surface. There is an opaque disc of radius 1 cm floating on the surface. The centre ‘O’ of the disc lies vertically above the source S. The liquid from the vessel is gradually drained out through a tap. What is the maximum height of the liquid for which the source cannot be seen at all?
Q.9. A ray PQ incident normally on the refracting face BA is refracted in the prism BAC made of material of refractive index 1.5. Complete the path of ray through the prism. From which face will the ray emerge? Justify your answer.
Q.10. Determine the value of the angle of incidence for a ray of light, travelling from a medium of refractive index μ1 = √2 into the medium of refractive index μ2 = 1, so that it just grazes along the surface of separation.