A light is refracted through a prism. The angle of deviation is :

Question

Accepted Answer

The correct answer is Option 1: The angle between the incident ray and the emergent ray.

1. **Explanation for Option 1:**
   The angle of deviation in the context of light refraction through a prism is defined as the angle between the direction of the incident ray and the direction of the emergent ray. When light passes through a prism, it is first refracted at the first surface, travels through the prism, and is then refracted again at the second surface. The incident ray enters the prism and the emergent ray exits the prism. The angle of deviation is the angle by which the path of the light is bent from its original path. This deviation occurs due to the change in speed of light as it moves from one medium to another, causing it to bend. Therefore, the angle of deviation is specifically the angle between the incident ray and the emergent ray, making Option 1 the correct answer.

2. **Explanation for why the other options are incorrect:**

- **Option 2: The angle between incident ray and refracted ray**
     This option describes the angle of refraction, not the angle of deviation. The angle of refraction is the angle between the incident ray and the refracted ray inside the prism, which is determined by Snell's Law. It is not the angle of deviation.

- **Option 3: The angle between refracted ray and emergent ray**
     This option refers to the internal angle within the prism between the refracted ray and the emergent ray. This is not the angle of deviation. The angle of deviation is concerned with the overall change in direction from the incident ray to the emergent ray, not the internal angles.

- **Option 4: The angle of prism**
     The angle of the prism is the angle between the two refracting surfaces of the prism itself. While this angle affects the amount of deviation, it is not the angle of deviation itself. The angle of deviation is specifically the angle between the incident and emergent rays, not the geometric angle of the prism.

In conclusion, Option 1 is the correct answer because it accurately describes the angle of deviation as the angle between the incident ray and the emergent ray, which is the standard definition in optics.