Ray Optics Mock Tests

A concave mirror has a focal length of 20 cm. An object is placed at 30 cm from the mirror. The image distance is:

A concave mirror forms a real image that is twice the size of the object. If the focal length is 20 cm, the object distance is:

A convex mirror has focal length f. An object is placed at distance u from it. The image distance v is given by:

The power of a lens is +5 D. Its focal length in cm when it is placed in a medium of refractive index 1.5 is (refractive index of lens material = 1.5):

A ray of light incident on a glass prism of refractive index 1.5 undergoes minimum deviation of 30 degrees. The angle of the prism is

A ray of light passes from air into a medium with refractive index 1.5. The angle of incidence is 30°. The angle of refraction is approximately:

For minimum deviation: μ = sin((A + δ_m)/2) / sin(A/2). Here A = 60° and δ_m = 30°. So μ = sin(45°) / sin(30°) = (1/√2) / (1/2) = 2/√2 = √2.

A convex lens of focal length 20 cm and a concave lens of focal length 10 cm are placed in contact. The power of the combination is: