Waec Physics 2008 Past Questions and Answers

Question 21:

• WAEC 2008

Water of mass 1.5kg is heated from from 30^oC to 80^oC using an electric kettle which is rated 5A, 230V. Calculate the time taken to reach the final destination [specific heat capacity of water 4200Jkg^-1K^-1]

A. 4.57 minutes
B. 5.02 minutes
C. 7.30 minutes
D. 10.04 minutes

Question 22:

• WAEC 2008

The working principle of a pressure cooker is based on the

A. Increase in the volume of steam inside it
B. Complete trapping of heat inside it
C. Increase in the pressure of the pot
D. Decrease in the pressure of the pot

Question 23:

• WAEC 2008

It takes a shorter time for a liquid to boil at the top of a mountain than at the base because at the top, the

A. Temperature is higher
B. Pressure is lower
C. Humidity is higher
D. Temperature is constant

Question 24:

• WAEC 2008

Light is considered as a transverse wave because it travels

A. Through material without causing disturbance of the medium
B. Through space with constant speed
C. In a direction parallel to the plane containing the electric and magnetic fields
D. In a direction perpendicular to the plane containing the electric and magnetic fields

Question 25:

• WAEC 2008

In the day time, it is possible to see under shady areas such as under a tree because light has undergone

A. Internal reflection
B. Refraction
C. Diffraction
D. Diffuse reflection