Available Answers

1. 1.

   Write true or false for each statement. Rewrite the false statement correctly.

   1. Equal volumes of two different substances have equal masses.
   2. Equal masses of two different substances have equal volumes.
   3. The density of a copper piece will change if its shape is changed, keeping the mass same.
   4. If the relative density of alcohol is 0.85, then it will occupy less volume than an equal amount (mass) of water.
   5. The density of iron depends on its mass, volume and its weight.
   6. Objects appear heavier when immersed in liquid.
   7. Iron placed on mercury surface will sink.
   8. Buoyant force is experienced when objects are immersed in fluids.
   9. Buoyant force acts in all directions.
2. 2.

   Fill in the blanks:

   1. The density of water in S.I. system is _______________.
   2. The unit of density in CGS system is _______________.
   3. If the weight of the body is more than the buoyant force, then the body will _______________.
   4. A submarine can sink or float by filling or emptying its _______________.
   5. One kg of salt will occupy more _______________ than one kg of iron.
   6. _______________  _______________ has no units.
   7. A brick will to be _______________ in water than in air.
   8. The relative density of water is _______________.
   9. An iceberg is dangerous for floating ships because it floats with only _______________ of its volume above water.
   10. 2.7 g cm^-3 of density will be equal to _______________ kg m^-3.
3. 3.

   Match the following :

   Column A	Column B
   Weight Buoyant force Apparent weight Relative density	has no units less than actual weight effective force due to gravity effective force due to liquid displaced

4. 4.

   Tick the most appropriate answer :

   (a) Density has the S.I. unit as

   1. g cm^-3
   2. g m^-3
   3. kg cm^-3
   4. kg m^-3

   (b) Density of water is 1 g cm-3. Its density in S.I. system is

   1. 10kg m^-3
   2. 100 kg m^-3
   3. 1000 kg m^-3
   4. none of the above

   (c) Density of iron in MKS system is 7800 kg m-3. Its density in CGS system will be

   1. 7.8 g cm^-3
   2. 78 g cm^-3
   3. 0.78 g cm^-3
   4. 780 g cm^-3

   (d) To obtain the density of a solid. we must know its

   1. mass and area
   2. mass and volume
   3. only mass
   4. only force

   (e) For a substance. the ratio of mass to the volume is known as

   1. relative density
   2. refractive index
   3. density
   4. none of the above

   (f) The unit of relative density is

   1. kg m^-3
   2. g m^-3
   3. kg cm^-3
   4. none of the above

   (g) The upward force experienced by a body immersed partially or completely in a fluid is known as

   1. upthrust
   2. down thrust
   3. horizontal force
   4. vertical force

   (h) Upthrust experienced by a body is equal to

   1. mass of the body
   2. apparent loss of weight of the body
   3. weight of the body
   4.  none of the above

   (i) If the weight of the body is less than the upthrust of the liquid in which it is submerged. then the body will

   1. float
   2. sink
   3. float and then sink
   4. none of the above

   (j) An ice cube floating on water has a fraction above water. This amount is

   1. 1/12th of total volume
   2. 11/12 of the total volume
   3. total volume
   4. 119th of the total volume
5. 5.

   Define density and relative density with their S.I. unit.

6. 6.

   Define buoyant force. Name the two factors on which the buoyant force depends.