Page 1 - HOME ASSIGNMENT-1(Obj& SUb.)
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SAI International School
                                                       Class-IX
                                                Subject-Chemistry
                                      Topic-Matter in our surroundings
                                             Sub topic- Evaporation
                OBJECTIVE QUESTIONS
                 Q.1     Assertion: We feel colder after taking bath with cold water.

                         Reason: Evaporation of hot water takes place faster which causes cooling.


                 Q.2     Assertion: A desert cooler cools better on a humid day.

                         Reason: Rate of evaporation is indirectly proportional to humidity.

                 Q.3     Assertion: We prefer to wear cotton clothes in summer.

                         Reason: Cotton is more comfortable than synthetic.


                 Q.4     Assertion: Tea becomes cold faster in a saucer than a cup.

                         Reason: Rate of evaporation is directly proportional to the surface area.

                 Q.5     Assertion: The water kept in a beaker under a fan evaporates faster than
                         the water in a beaker kept in a cupboard.

                         Reason: Rate of evaporation is indirectly proportional to the wind speed.

                 Q.6     Which condition out of the following will increase the evaporation of water?


                         a) increase in temperature of water

                         b) decrease in temperature of water

                         c) less exposed surface area of water

                         d) adding common salt to water

                 Q.7     During summer days, water kept in an earthen pot(pitcher) becomes cool
                         because of the phenomenon of:


                         a) diffusion

                         b) transpiration

                         c) osmosis

                         d) evaporation

                 Q.8     Humidity is amount of


                         a) water vapour in air



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