Available Answers

1. 1.

   Tick the most appropriate answer.

   1. Which of the following is the smallest unit of matter that has an independent existence?

   1. element
   2. ion
   3. atom
   4. molecule

   2. On heating a substance, the intermolecular forces between the molecules of the substance

   1. decrease.
   2. increase.
   3. remain unchanged.
   4. change randomly.

   3. What is the density of a solid of mass 5 g. which when immersed in water filled in a measuring cylinder, raise its level by 5 mL?

   1. 5 g/mL
   2. 25 g/mL
   3. 1 g/mL
   4. 1 mL/g

   4. Which of the following shows no significant change in its density when heated or cooled?

   1. solid
   2. liquid
   3. gas
   4. all of these

   5. When a deep-sea diver dives deeper into the sea, the pressure of the water on him

   1. decrease.
   2. increase.
   3. remains unchanged.
   4. changes randomly.

   6. Which of the following is the unit of moment of force?

   1. N/m²
   2. N m
   3. J
   4. Pa

   7. The energy possessed by a body due to its motion is known as its

   1. gravitational potential energy.
   2. elastic potential energy.
   3. kinetic energy.
   4. total mechanical energy.

   8. The physical quantity that gives the rate at which energy is transferred per unit time is

   1. force.
   2. displacement.
   3. work.
   4. power.
2. 2.

   Fill in the blanks.

   1. The process of conversion of a liquid into its solid state at a particular temperature on cooling is known as _______________________________.
   2. ____________________ and ______________________ are some of the substances that sublime at room temperature.
   3. It is easier to swim in sea water than in river water as sea water is _________________________ than river water.
   4. _______________________ currents are set up in fluids on heating due to the constant upward and downward circulation of the fluid.
   5. The pressure exerted by kerosene oil is __________________________ than that exerted by water.
   6. Moment of a force depends upon the ___________________ and ______________________.
   7. The work done by a force ___________________________ if the displacement in the direction of the force increases.
   8. _______________________________ energy of an object increases with the increase in its height from the ground.
3. 3.

   Explain the process of condensation with the help of kinetic theory of matter.

4. 4.

   How can kinetic theory of matter be used to distinguish between the three states of matter?

5. 5.

   How does the density of different states of matter vary with temperature?

6. 6.

   What is a Eureka can? How can it be used to determine the volume of an irregular solid?