for a ray of light incident normally on one face of the prism prace course of the ray measure the delta angle explain briefly do this for prism with angleA=60,45,90
To determine the deviation angle of a ray of light incident on a prism, where the incident angle is normal (i.e., the ray is perpendicular to the face of the prism), you need to consider the properties of the prism and the angle of the prism itself.
A prism typically has two triangular faces and a base. The angle between the two faces is known as the apex angle, which is different for each prism. In your question, you mentioned three prisms with angles A of 60°, 45°, and 90°. Let's calculate the deviation angle for each of these prisms:
1. Prism with angle A = 60°:
When the incident ray is normal to one face of the prism with an apex angle of 60°, the ray passes through it undeviated. Thus, the deviation angle is 0°.
2. Prism with angle A = 45°:
For a prism with an apex angle of 45°, the deviation angle can be calculated using the formula:
Deviation Angle = (Angle A - 90°) + (Angle A/2)
Substituting the angle A as 45° into the formula:
Deviation Angle = (45° - 90°) + (45°/2)
Deviation Angle = -45° + 22.5°
Deviation Angle = -22.5°
3. Prism with angle A = 90°:
When a ray of light is incident normally on a face of a prism with a 90° apex angle, the ray will undergo maximum deviation. In this case, the deviation angle is twice the apex angle.
Deviation Angle = 2 * Angle A
Substituting the angle A as 90° into the formula:
Deviation Angle = 2 * 90°
Deviation Angle = 180°
So, for the prism with angle A = 60°, the deviation angle is 0°. For the prism with angle A = 45°, the deviation angle is -22.5°. And for the prism with angle A = 90°, the deviation angle is 180°.