Physics Past Questions and Answers

I. The earth is not spherical but elliptical in shape
II. Variation in latitude and longitude
III. Rotation of the earth on its axis
IV. Variation in the density of the earth
On which combination of the above does the weight of an object vary on the earth's surface?

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

Question 7:

The efficiency of a machine is always less than 100% because the

A Work output is always greater than the work input
B Load lifted is always greater than the effort applied
C Effort applied is always greater than the load lifted
D Velocity ratio is always greater than the mechanical advantage

Question 8:

Which of the following consists entirely of vector quantities?

A Velocity, magnetic fulx and reaction
B Tension, magnetic flux and mass
C Displacement, impulse and power
D Work, pressure and moment

Question 9:

Ice cubes are added to a glass of warm water. The glass and water are cooled by

A Conduction only
B Convection only
C Conduction and convection
D Convection and radiation

Question 10:

A ray of light strikes a plane mirror at an angle of incidence of 35°. If the mirror is rotated through 10°, through what angle is the reflected ray rotated?

A 70Â°
B 45°
C 25Â°
D 20Â°