Waec Physics 1996 Past Questions and Answers

Question 16:

• WAEC 1996

The pressure of a fixed mass of gas is 2.0 x 10⁵Nm^-2 at a known temperature. Assuming that the temperature remains constant, what will be the pressure of the gas if its volume is halved?

A. 1.0x10⁵Nm^-2
B. 2.0X10⁵Nm^-2
C. 3.0x10⁵Nm^-2
D. 4.0 x10⁵Nm^-2
E. 5.0 x10⁵Nm^-2

Question 17:

• WAEC 1996

Which of the following statements is not correct?

A. Heat energy can be transformed into mechanical energy
B. That total heat content of a body is the sum of the kinetic energies of its molecules
C. Lf a body is heated, its molecules move faster.
D. Lf a body is cooled, molecular movement remains constant.

Question 18:

• WAEC 1996

A 400W immersion heater is used to heat a liquid of mass 0.5kg. lf the temperature of the liquid increases by 2.5^oC in one second, calculate the specific heat capacity of the liquid (Neglect heat losses to the surroundings)

A. 80 Jkg^-1K^-1
B. 320Jkg^-1K^-1
C. 500Jkg^-1K^-1
D. 1200J kg^-1K^-1
E. 2000J kg^-1K^-1.

Question 19:

• WAEC 1996

What is the difference in the amount of heat given out by 4kg of steam and 4kg of water when both are cooled from 100oC to 80oC? (Specific latent heat of steam = 2.260,000J kg-1) (Specific heat capacity of water =4,200 J kg-1)

A. 336,000J
B. 672,000J
C. 8,704,000J
D. 9,040,000J
E. 9,376,000J

Question 20:

• WAEC 1996

The heating element in an electric kettle is usually located near the bottom of the kettle because

A. Water is a good conductor of heat
B. Heat can be more quickly radiated to all parts of the water
C. No heat can be lost to the surroundings
D. The convectional currents which are set up can carry heat to all parts of the water
E. The molecules of the heating element can carry heat to all parts of the water.