Change of State - Jamb Physics Past Questions and Answers

Question 1:

• JAMB 1978

An ice cube floats in a glass of water filled to the brim. What happens when the ice melts?

A. The water level remains the same
B. There is a drop in the level of water in the glass due to condensation on its outside
C. The water in the glass overflows
D. The level of water drops because melted ice occupies less volume
E. None of the above is correct

Question 2:

• JAMB 1978

The statements below were made by some students describing what happened during the determination of the melting point of solids.
i. the temperature of the solid was solid until melting started
ii. the temperature of the solid rose until melting started
iii. during melting, the temperature was rising
iv. during melting, the temperature was constant
v. the temperature continued to rise after all the solid had melted
vi. the temperature stopped rising after all the solid had melted. Which of the following gives correct statements in the right order?

A. Ii, iv, and v
B. Ii, iii and vi
C. I, iii and vi
D. I, iii and v
E. I, iv and v

Question 3:

• JAMB 1978

The latent heat of fusion of ice is 80cal g^-1. How much heat is required to change 10g of ice at Q^oC into water at the same temperature?

A. 80 cal
B. 10 cal
C. 8 cal
D. 800 cal
E. 400 cal

Question 4:

• JAMB 1978

The following are some units i. Ns ii. Mm iii. Nm^-2 iv. J^oK^-1. What are the units of latent heat?

A. I
B. Ii
C. Iii
D. Iv

Question 5:

• JAMB 1978

The amount of heat required to raise the temperature of a body is

A. Thermal energy
B. Thermal conduction
C. Heat loss
D. Specific heat capacity
E. Thermal capacity