Physics Past Questions and Answers

Which of the following statements is/are correct? I. Pure water freezes at 0^oC under normal pressure ll. Water has its highest density at 4^oC. III. The volume at 4^oC,

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

Question 252:

A given mass of gas at a temperature of 30°C is trapped in a tube of volume V. Calculate the temperature of the gas when the volume is reduced to two-third of its original value by applying a pressure twice the original value.

A 71^oC
B 40^oC
C 131^oC
D 313^oC
E 404^oC

Question 253:

Which of the following colours of surfaces will radiate heat energy best?

A Red
B White
C Black
D Yellow
E Blue

Question 254:

A gas which obeys Charles’ law exactly has a volume of 283cm³ at 10^oC. What is its volume at 30^oC?

A 142cm³
B 293cm³
C 303cm³
D 566cm³
E 849cm³

Question 255:

Which of the following best explains why a person suffers a more severe burn when his skin is exposed to steam than when boiling water pours on his skin?

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