Change of State - Jamb Physics Past Questions and Answers

Question 11:

• JAMB 1981

Heat was supplied to a block of ice at 0^oC until half of it melted. Which of the following statements is true?

A. The temperature rises and the ice expand
B. The temperature remains constant and the volume of the ice decreases
C. The ice gives out heat as it melts and the temperature decreases
D. The mass remains constant and the temperature increases
E. The temperature decreases because some heat is lost

Question 12:

• JAMB 1981

Change of state is accompanied by change of

A. Temperature
B. Volume
C. Heat content
D. Temperatureb and volume
E. Volume and heat content

Question 13:

• JAMB 1982

When equal weights of iron and water are subjected to equal supply of heat, it is found that the piece of iron become more hotter than water after a short time because

A. The specific heat of iron is higher than that of water
B. Iron is in solid form
C. Water is in liquid form
D. The specific heat of water is higher than that of iron
E. The specific heat of iron is infinite

Question 14:

• JAMB 1982

250g of lead at 170^oC is dropped into 100g of water at 0^oC. If the final temperature is 12^oC, the specific heat of lead is (specific heat of water is 4,200J/kg^oC)

A. 39.5J/kg^oC
B. 50.4J/kg^oC
C. 127.6J/kg^oC
D. 154.6J/kg^oC
E. 173.4J/kg^oC

Question 15:

• JAMB 1982

A heater marked 50W will evaporate 0.005kg of boiling water in 50 seconds. The specific latent heat of vaporization of water in J/kg is

A. 5.0 x 10⁶
B. 1.0 x 10⁶
C. 2.5 x 10⁶
D. 2.5 x 10⁵
E. 5.0 x 10⁵