Physics Past Questions and Answers

What is the frequency of the sound made by a siren having a disc with 32 holes and making 25 revolution per seconds?

A 80Hz
B 600Hz
C 800Hz
D 1600Hz

Question 22:

Which of the following properties make the convex mirror useful as a driving mirror? i. the image is real. ii. the image is erect. iii. it has a wide field of view. iv. the image is magnified.

A I, ii, and iv
B I, ii, iii
C Ii and iii
D I and iii

Question 23:

When an object is placed very close to the pole of a concave mirror, the virtual image obtained is

A Diminished and upright
B Diminished and inverted
C Enlarged and inverted
D Enlarged and upright

Question 24:

A concave mirror has a radius of curvature of 36cm. At what distance from the mirror should an object be placed to give a real image three times the size of the object?

A 12cm
B 24cm
C 48cm
D 108cm

Question 25:

Which of the following statements is CORRECT about a long-sighted boy who does not put on glasses?

A He cannot see distant objects clearly
B Rays of light from a close object are focused in front of his retina
C His eye ball is too long
D Parallel rays of light are focused behind his retina