Physics Past Questions and Answers

A room is heated by means of a charcoal fire, An occupant of the room standing away from the fire is warmed mainly by

A Convection
B Radiation
C Conduction
D Reflection

Question 637:

A boy timed 30 oscillations of a certain pendulum thrice and obtained 1min. 10s, 1min. 12s and 1min. 7s respectively.The mean period of oscillation of the pendulum is

A 0.14s
B 0.43s
C 2.32s
D 6.97s

Question 638:

Which of the following is TRUE of light and sound waves?

A They both transmit energy
B They both need a mediumfor propagation
C They are both transverse waves
D Their velocities in air are equal

Question 639:

The image in a pin-hole camera is

A Errect and formed by refraction through a lens
B Virtual and formed by dispersion
C Erect and gets sharper as the hole becomes larger
D Inverted and formed by the light from each point travelling in a straight line

Question 640:

When a plane mirror at which a ray is incident is rotated through an angle \( \theta \), the reflected ray will be rotated through

A \(\frac{1}{2}\)\(\theta\)
B \(\theta\)
C 2\(\theta\)
D 3\(\theta\)