Quantity of Heat - Jamb Physics Past Questions and Answers

Question 21:

• JAMB 2003

If 1.2 x 10⁶J of heat energy is given off in 1 sec from a vessel maintained at a temperature gradient of 30Km^-1, the surface area of the vessel is

A. 1.0 x 10²m²
B. 9. 0 x 10²m²
C. 1.0 x 10³m²
D. 9.0 x 10⁴m²

Question 22:

• JAMB 2004

A 50W electric heater is used to heat a metal block of mass 5kg. If in 10 minutes a temperature rise of 12^oC is achieved, the specific heat capacity of the metal is

A. 400 J kg^-1K^-1
B. 500 J kg^-1K^-1
C. 390 J kg^-1K^-1
D. 130 J kg^-1K^-1

Question 23:

• JAMB 2006

An immersion heater rated 2.0A, 240V is used to boil water from temperature 52°c to 100°c. If the mass of the water is 2.5kg. determine the time taken to boil the water.
[specific heat capacity of water = 4.2 x 10³ jkg^-1 k^-1]

A. 1.05 x 10³s
B. 1.05 x 10⁵s
C. 1.05 x 10²s
D. 1.05 x 10⁴s

Question 24:

• JAMB 2007

2 kg of water is heated with a heating coil which draws 3.5 A from a 200 V mains for 2 minutes. what is the increase in temperature of the water?
[specific heat capacity of water = 4200 jkg ^-1k^-1]

A. 30°
B. 25°
C. 15°
D. 10°

Question 25:

• JAMB 2008

A block of aluminum is heated electrically by a 25 W heater. if the temperature rises by 10°C in 5 minutes, the heat capacity of the aluminum is?

A. 850 JK^-1
B. 750 JK^-1
C. 650 JK^-1
D. 500 JK^-1