For a ray of light to suffer total internal reflection it has to pass from : A. Glass to water B. Water to glass C. Air to water D. Air to glass

The correct answer is: A. Glass to water

Total internal reflection is an optical phenomenon that occurs when light passes from a medium with a higher refractive index to a medium with a lower refractive index at an angle greater than the critical angle. The critical angle is the angle of incidence at which the light ray is refracted so that it travels parallel to the boundary between the two media.

For total internal reflection to occur, the following conditions must be met:

1. The light must be traveling from a medium with a higher refractive index to a medium with a lower refractive index.
2. The angle of incidence must be greater than the critical angle.
3. The light must be traveling in a straight line.

If any of these conditions are not met, then total internal reflection will not occur.

In the case of the question, the light is traveling from glass to water. The refractive index of glass is 1.52, while the refractive index of water is 1.33. Therefore, the light is traveling from a medium with a higher refractive index to a medium with a lower refractive index. The angle of incidence is also greater than the critical angle, which is 42 degrees for glass and water. Therefore, the light will suffer total internal reflection.

The other options are incorrect because the light is not traveling from a medium with a higher refractive index to a medium with a lower refractive index. In option B, the light is traveling from water to glass. The refractive index of water is 1.33, while the refractive index of glass is 1.52. Therefore, the light is traveling from a medium with a lower refractive index to a medium with a higher refractive index. In option C, the light is traveling from air to water. The refractive index of air is 1.00, while the refractive index of water is 1.33. Therefore, the light is traveling from a medium with a lower refractive index to a medium with a higher refractive index. In option D, the light is traveling from air to glass. The refractive index of air is 1.00, while the refractive index of glass is 1.52. Therefore, the light is traveling from a medium with a lower refractive index to a medium with a higher refractive index.