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Physics - Geometrical Optics Question with Solution | TestHub

PhysicsGeometrical OpticsReflection at curved surfaceMedium2 minQB
PhysicsMediumsingle choice

In the figure shown a thin parallel beam of light is incident on a plane mirror m1 at small angle ‘q’. m2 is a concave mirror of focal length ‘f’. After three successive reflections of this beam the x and y coordinates of the image is

 

image.png

Options:

Answer:
D
Solution:

Solution:

Let the incident beam be parallel to the x-axis.

1. First reflection (M₁): The beam reflects at an angle with the normal. The reflected ray makes an angle with the incident direction.

2. Second reflection (M₂): The ray hits the concave mirror M₂. Since the incident ray passes through the focus, it reflects parallel to the principal axis.

3. Third reflection (M₁): The ray reflects off M₁ again. The final image is formed at a distance from M₂.

 

The final image coordinates are and .

 

The incident ray is parallel to the x-axis, so its initial y-coordinate is .

After the first reflection from M₁, the ray makes an angle with the x-axis.

The concave mirror M₂ is placed at .

The focal length of M₂ is .

The incident ray on M₂ is parallel to the principal axis (x-axis) after the second reflection.

The final image is formed at a distance from M₂.

The x-coordinate of the image is .

The y-coordinate of the image is (due to the small angle approximation and the reflection from M₁).

 

The final answer is .

Stream:JEESubject:PhysicsTopic:Geometrical OpticsSubtopic:Reflection at curved surface
2mℹ️ Source: QB

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