Physics Past Questions and Answers

A Motor Tyre is inflated to pressure of 2.0 x 10⁵Nm^-2 when the temperature of air is 27^oC. What will be the pressure in it at 87^oC assuming that the volume of the Tyre does not change?

A 2.6 x 10⁵Nm^-2
B 2.4 x 10⁵Nm^-2
C 2.2 x 10⁵Nm^-2
D 1.3 x 10⁵Nm^-2

Question 17:

When 100g of liquids L1 at 78°C was mixed with Xg of liquid L2 at 50°C, the final temperature was 66°C. Given that the specific heat capacity of L2is half that of L1, find x

A 50g
B 100g
C 150g
D 200g

Question 18:

Heat is supplied to a test tube containing 100g of ice at its melting point. The ice melts completely in 1 min.What is the power rating of the source of heat? [Latent heat of fusion of ice = 336Jg^-1]

A 336W
B 450W
C 560W
D 600W

Question 19:

If a room is saturated with water vapour, the temperature of the room must be

A At 0^oC
B Above the dew point
C At 100^oC
D Below or at the dew point

Question 20:

Two similar kettles containing equal masses of boiling water are placed on a table. If the surface of one is highly polished and the surface of the other is covered with soot, Which of the following observations is correct

A The two kettles will cool down at the same rate
B The polished kettle cools down more quickly by conduction
C The kettle covered with soot cools down more quickly because it is a good radiator
D The kettle covered with soot cools down more quickly by the process of heat convection