Physics Past Questions and Answers

At 4°c, the volume of a fixed mass of water is?

A Constant
B Minimum
C Maximum
D Zero

Question 1432:

An electric heater rated 220v, 1000 w is immersed into a bucket full of water, calculate the mass of water if the temperature changes from 30°c to 100°c and the current flows for 300seconds. [specific heat capacity of water = 4200 jkg-1 K-1]

A 4.28 kg
B 42.86 kg
C 1.02 kg
D 7.14 kg

Question 1433:

If the pressure of the vapour on top of an enclosed liquid is equal to the atmospheric pressure, what will be the temperature of the liquid enclosed?

A Room temperature
B Boiling point
C Freezing point
D Standard temperature

Question 1434:

A heating coil rated 1000 W is used to boil off completely 2 kg of boiling water. the time required to boil of the water is_______ [Special latent heat of Vaporization of water = 2.3 x 106 Jkg-1]

A 1.15 x 104s
B 1.15 x 103s
C 4.6 x 104s
D 4.6 x 103s

Question 1435:

It is observed that water will wet a clean glass because the

A Cohesion of water to glass is stronger than the cohesion of water molecules
B Adhesion of water molecules is weaker than the cohesion of water to glass
C Cohesion of water to glass is weaker than the cohesion of water molecules
D Adhesion of water molecules is stronger than the cohesion of water molecules