Physics Past Questions and Answers

A given mass of gas has a pressure of 80Nm^-2 at a temperature of 47^oC. If the temperature is reduced to 27^oC with the volume remaining constant, the new pressure is

A 46.0 Nm^-2
B 75.0 Nm^-2
C 80.0 Nm^-2
D 85.3 Nm^-2
E 139.4 Nm^-2

Question 32:

Which of the following is a reason why a concrete floor feels colder to the bare feet than a mat on the same floor during the rainy season?

A A mat if s better conductor of heat than the feet
B Mat losses heat to the bare feet at a faster rate than concrete floor
C Mat losses heat to the bare feet while the concrete floor extracts heat from them
D Concrete floor is a better conductor of heat than the mat
E Mat is a better conductor of heat than the floor

Question 33:

In which of the following is the expansion of solids a disadvantage?

A The fitting of wheels in rims
B Fire alarms
C The thermostat
D The bimatellic thermometer
E The balance wheel of a watch

Question 34:

Which of the following best explains a person suffers more severe burns when his skin is exposed to steam than when boiling water is poured onto his skin?

A Steam is at a higher temperature than boiling water
B Steam posses greater heat energy per unit-mass than boiling water
C Steam spreads more easily over a wider area of the skin than boiling water
D Steam panetrates more easily over a wider area of the skin than boiling water
E The specific latent heat of vaporization is released in changing from boiling water to steam

Question 35:

Which of the following statements about radiant heat is/are not correct?
I. radiant heat cannot travel through a vacuum
II. rough surfaces emit radiant heat more than polished surfaces
III. Dark surfaces absorb radiant heat more than bright surfaces

A I only
B II only
C III only
D I & II only
E II & III only