Waec Physics 1989 Past Questions and Answers

Question 11:

• WAEC 1989

An engine raises 1000kg of water through a height of 60m in 20s. What is the power of the engine? (Take g = 10ms^-2>).

A. 120,000 W
B. 30,000 W
C. 333 W
D. 300 W
E. 30 W

Question 12:

• WAEC 1989

A thermometer has its stem marked in millimeter instead of degree Celsius. The lower fixed point is 30mm and the upper is 180mm. Calculate the temperature in degree celsius when the thermometer reads 45mm.

A. 67.5^oC
B. 30.0^oC
C. 25.0^oC
D. 15.0^oC
E. 10.0^oC

Question 13:

• WAEC 1989

Which of the following surfaces will radiate heat energy best?

A. Red
B. White
C. Black
D. Yellow
E. Blue

Question 14:

• WAEC 1989

Which of the followiempeng statements is/are not correct?

A. Evaporation takes place only at the surface of the liquid
B. Boiling takes place throughout the volume of the liquid
C. Evaportaion takes place at all temperatures
D. Boiling takes place at a particular temperature for a liquid at a fixed external pressure
E. The boiling point of a liquid is not affected by impurities

Question 15:

• WAEC 1989

Water in an open container boils at a lower temperature when heated at the top of a mountain than at sea-level because at the top of a mountain the

A. Relative humidity is higher than at sea-level
B. Rays of the sun adds more heat to the water
C. Temperature is lower than that at sea-level
D. Pressure is lower than that at sea-level
E. Pressure is more than that at sea-level