Under which of the following conditions is workdone

• A. A man supports a heavy food above his head with his hands
• B. A boy climbs onto a table
• C. A man pushes unto a table
• D. A woman holds a pot of water

Counting of currency notes with moist fingers is based on the principles of?

• A) diffusion
• B) cohesion
• C) adhesion
• D) viscosity

A fixed mass of gas of volume 600cm³ at a temperature of 27^oC is cooled at constant pressure to a temperature of 0^oC. What is the change in volume?

• A. 54cm²
• B. 273cm²
• C. 300cm²
• D. 546cm²

In a photocell, light energy is converted to

• A. Electrical energy
• B. Chemical energy
• C. Heat energy
• D. Mechanical energy

At what distance from a simple microscope must an object be placed so that the image 5 times the size of the object is produced 20cm from the lens?

• A. 2cm
• B. 3.3cm
• C. 4cm
• D. 5cm

Heat transfer by convection in a liquid is due to the

• A. Latent heat of vaporization of the liquid
• B. Increased vibration of the molecules of the liquid about theit mean position
• C. Variation of density of the liquid
• D. Expansion of the liquid as it is heated

A car battery rated 45 A H is charged with a charger whose rating is 2.5A.How long will it take to charge the battery full?

• A. 10 hrs
• B. 18 hrs
• C. 20 hrs
• D. 25 hrs

The amount of energy required to change a kilogram of ice block into water without a change in temperature is?

• A. specific latent heat of fusion of ice
• B. specific heat capacity of rice
• C. heat capacity of rice
• D. specific heat of vaporization of rice

Explain the following terms:

(a) tensile stress;

(b)Young’s modulus

To produce a parallel beam of light from a concave mirror, the distance at a which the lamp should be placed from the mirror is equal to

• A. the focal length
• B. two times the focal length
• C. the distance of the image
• D. two times the radius of curvature