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A ray of light is incident on a plane mirror at an angle of 40° with respect to surface normal. When it gets reflected from the mirror, it undergoes a deviation of
Explanation
The correct answer is Option 2 (100°).
According to the laws of reflection, the angle of incidence (i) is equal to the angle of reflection (r). Given that the ray is incident at 40° to the surface normal, the angle of reflection is also 40°.
The angle of deviation (δ) is defined as the angle between the original path of the incident ray and its reflected path. Mathematically, if a light ray were to travel straight without the mirror, it would cover a total linear angle of 180°. The deviation is calculated using the formula: δ = 180° - (i + r) or δ = 180° - 2i.
- Substituting the values: δ = 180° - (40° + 40°)
- δ = 180° - 80°
- δ = 100°
Option 4 (80°) is incorrect as it represents the total angle between the incident and reflected rays, not the deviation from the original path.
SIMILAR QUESTIONS
A ray of light is incident on a plane mirror at an angle 30° with the normal at the point of incidence. The ray will be deviated from its incidence direction by what angle ?
A ray of light is incident on a plane mirror at an angle 30° with the normal at the point of incidence. The ray will be deviated from its incidence direction by what angle ?
Which one of the following is the correct angle between the incident and reflected rays when a ray of light incident normally on a plane mirror?
A ray of light is incident normally on one of the faces of right angled isosceles prism as shown below. It undergoes total internal reflection from hypotenuse. Which one of the following is the minimum refractive index of the material of the prism?
When a mirror is rotated by an angle of θ, the reflected ray will rotate by:
- A) 0°
- B) θ / 2
- C) θ
- D) 2θ
(Note: The default options displayed by the platform belong to a different question due to an error. Please use the options listed above to answer.)