A concave lens forms the image of an object which is:

1. virtual, inverted, and diminished
2. virtual, upright, and diminished
3. virtual, inverted, and enlarged
4. virtual, upright, and enlarged.

For a convex lens when the object is at 2F₁, then image is formed at :

1. F₂
2. 2F₂
3. beyond 2F₂
4. infinity

For a concave lens, when the object is at a distance equal to the focal length of the lens, the image is formed at :

1. optical centre
2. second focus
3. first focus
4. mid point between the optical centre and second focus of the lens

Assertion (A): The focal length of a lens does not change when red light is replaced by blue light.

Reason (R): The focal length of a lens depends on the refractive index of material of lens.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true and R is not the correct explanation of A.
3. assertion is false but reason is true.
4. assertion is true but reason is false.