Physics Past Questions and Answers

I. Moon.
II. Sun.
III.street light.
IV. stars.
Which of these above is a natural source of light?

A II, III, and IV only
B I, II and III only
C III and IV only
D II and IV only

Question 22:

An object is placed 5 cm from the pole of a concave mirror. if the focal length of the mirror is 10 cm. what is the image distance?

A 10 cm in front of the mirror.
B 5 cm in front of the mirror
C 10 cm behind the mirror
D 5 cm behind the mirror

Question 23:

Calculate the position of an object placed in front of a convex mirror having focal length of 12 cm such that an image is formed 6 cm away from the mirror

A 4. 0 cm
B 3. 0 cm
C 12.0 cm
D 9.0 cm

Question 24:

If the refractive index of crown glass is 1.51, its critical angel is.

A 48.6Â°
B 22.5°
C 41.5Â°
D 45.0Â°

Question 25:

When light passes through two media x and y of refraction indices 1.51 and 1.33 respectively, the speed of light in

A X is same as in y
B X and y is same as in vacuum
C X is higher than in y
D Y is higher than in x