The quantity of heat needed to raise the temperature of a body by 1K is the body's

• A. Heat capacity
• B. Internal energy
• C. Specific heat capacity
• D. Latent heat of fusion

A man standing 300m away from the wall sounds a whistle. The echo from the wall reaches him 1.8sec. later, calculate the velocity of sound in air

• A. 540.0ms^-1
• B. 333.3ms^-1
• C. 270.0ms^-1
• D. 166.7ms^-1

The purpose of a dielectric material in a parallel plate capacitor is to

• A. increase its capacitance
• B. decrease its capacitance
• C. insulate the plate from each other
• D. increase the magnetic field between the plates

Explain plane polarisation of light

The capacitance of a parallel-plate capacitor is increased by making the area of the plates

• A. small and their seperation large
• B. large and their seperation small
• C. and their seperation small
• D. and their seperation equal

A 200 kg load is raised using a 110 m long lever as shown in the diagram below. The load is 10m from the pivot P. If the efficiency of the the lever is 80%, find the effort E required to lift the load.

[Take g = 10ms^-2]

• A. 250
• B. 300
• C. 450
• D. 200

A solid plastic cube of side 0.2m is submerged in a liquid density of 0.8kg\(m^{-3}\). Calculate the upthrust of the liquid on the cube (g=10\(ms^{-2}\)

• A. 0.064N
• B. 0.025N
• C. 0.016N
• D. 0.008N

An electron of mass 9. 1 x 10\(^{-31}\) kg moves with a velocity of 4.2 x 10 ms\(^{-1}\) between the cathode and anode of an x-ray tube. Calculate the wavelength. (Take Planck's constant h = 6.6 x 10\(^{-34}\) J S)

A charge of 1.0 x 10^-5 Coulombs experience force of 40N at a certain point in space. What is the electric field intensity?

• A. 8.00 x 10⁶NC^-1
• B. 4.00 x 10⁶NC^-1
• C. 4.00 x 10^-4NC^-1
• D. 2.00 x 10^-4NC^-1

A 20kg mass is to be pulled up a slope inclined at 30^o to the horizontal. If the efficiency of the plane is 75%, the force required to pull the load up the plane is [g = 10ms^-2]

• A. 13.3N
• B. 73.5N
• C. 133.3N
• D. 53.2N