The phenomenon which occurs when light changes direction as it passes from one medium to another is called

• A. reflection
• B. polarisation
• C. interference
• D. refraction

The handle of a screw jack is 35 cm long and pitch of the screw is 0.5 cm. What force must be applied at the end of the handle to lift a load of 2000N, if the efficiency of the jack is 30% [π = 22/7]?

• A. 152.0N
• B. 132.0N
• C. 15.2N
• D. 440.0N

The time rate of change of displacement is known as

• A. speed
• B. velocity
• C. impulse
• D. acceleration

The graph of density against temperature for water is correctly illustrated by

• A. I
• B. II
• C. III
• D. IV

Which of the following statements about the electromagnetic waves is correct?

• A. radio waves have longer frequencies than x-rays
• B. x-rays have the longest wavelength
• C. some of the waves travel at 3.0 x 10⁸ms^-1
• D. white light occupies a region beyond ultraviolet rays

The following statements are observations made about a towing vehicle and a bus that is being towed

I. The force exerted on the bus by the towing vehicle is of the same magnitude as the force that the bus exerts on the road.

II. The force exerted on the bus by the towing vehicle is of the same magnitude as the force exerted on the towing vehicle by the bus.

III. The towing vehicle exerts a force on the bus greater than the force exerted by the bus on the towing vehicle.

IV. The towing vehicle exerts a force on the bus that is the same as the force the road exerts on the towing vehicle.

Which of the following statements is/are correct?

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

(a)

In the diagram illustrated, a body of mass m slides on an inclined plane. Show that the coefficient Mg of friction between the surfaces in contact is tan \(\theta\).

A spiral spring with a metal extends by 10.5 cm in air. When the metal is fully submerged in water, the spring extends by 6.8 cm. Calculate the relative density of the metal. (Assume Hooke's law is obeyed)

Light travelling through a small pinhole usually does not make a shadow with a distinct sharp edge because of

• A. diffraction
• B. interference
• C. reflection
• D. refraction

A man walks 1km due east and then 1 km due north His displacement?

• A. √2km N 45°E
• B. 1km N 30°E
• C. 1km N 15°E
• D. √2km N 60°E

According to kinetic molecular model, in gases

• A. The molecule are very fast apart & occupy all the space made available
• B. The particles occur in clusters with molecules slightly farther apart
• C. The particles vibrate about fixed positions and are held together by the strong intermolecular bond between them
• D. The particles are closely packed together, they occupy minimum space & are usually arranged in a regular pattern