Physics Past Questions and Answers

Iron at 30^oC feels colder to the hand than wood at 28^oC because

A Their linear expansivities are not equal.
B The temperature of the iron is higher than that of the wood
C Iron is a better radiator of heat than wood
D Iron conducts heat more quickly from the hand than wood

Question 2857:

An iron rod of length 50m and at a temperature of 60^oC is heated to 70^oC. Calculate its new length. (Linear expansivity of iron = 1.2 x 10^-5K^-1)

A 50.006m
B 50.060m
C 51.600m
D 51.200m

Question 2858:

The heat capacity of a substance is the energy

A Required to raise the temperature of a unit mass of the substance by one degree.
B Required to raise the temperature of the substance by one degree
C Absorbed by the substance at constant temperature
D Lost by a unit mass of the substance.

Question 2859:

The temperature of a piece of metal of mass 9 g is raised from 10^oC to 110^oC when it absorbs 108J of heat energy. Determine the specific heat capacity of the metal in J kg^-1K^-1

A 1.2
B 12.0
C 120.0
D 1200.0

Question 2860:

Which of the following statements is not correct?

A A sea breeze is due to convection in air
B Cotton materials are better than woollen ones for use in hot weather
C Convectional currents play an important role in the cooling of the engine of a motor car
D The vacuum space in a flask helps to reduce heat loss by radiation.