Page 1 - HA
P. 1

SAI INTERNTIONAL SCHOOL
                                                       Class 7
                                                Home Assignment
                                                 Subject- Physics
                                           Ch- Heat and Temperature
                                              Subtopic- Convection


           Find the odd one out.(Q.No. 1-4)                                                             Marks
             1.      a)  Conduction                                                                        1
                     b)  Convection
                     c)  Fusion
                     d)  Radiation
             2.      a)  Ventilation by exhaust fan                                                        1
                     b)  Land breeze
                     c)  Sea breeze
                     d)  Thermos flask
             3.      a)  Convection current                                                                1
                     b)  Hot air rises
                     c)  Electric shock
                     d)  Cold air is denser.
             4.      a)  Fluids                                                                            1
                     b)  Particles tightly packed.
                     c)  Actual movement of particles for transfer of heat.
                     d)  Particles free to move.
         For Assertion & Reason question follow the following directions.
         DIRECTION: Each of these questions contains an Assertion followed by Reason. Read them
         carefully and answer the question on the basis of following options. You have to select the one that
         best describes the two statements.
         (a) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
         (b) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
         (c) If Assertion is correct but Reason is incorrect.
         (d) If Assertion is incorrect but Reason is correct.
         (e) If Assertion & Reason both are incorrect.

             5.  Assertion: Gliders pilots keep their glider in the sky using rising air above the land.   1
                 Reason: Hot air is lighter which rises up and provide convection currents.
             6.  Assertion: Room heaters are fitted on the floor of the room.                              1
                 Reason: Gas particles are loosely packed and free to move.
             7.  Assertion: In land breeze, air moves from land to sea.                                    1
                 Reason: Air above the land is lighter than that above the sea.
             8.  Assertion: Heat transfer in solid, liquid and gas takes place through conduction          1
                 Reason: Particles inLiquid and Gases are free to move.
             9.  Assertion: Exhaust fans are fitted near the ground.                                       1
                 Reason: Hot air sinks down and escapes from the room.
             10.  Assertion: Room heaters are fitted near the ceiling of the room.                      1
                 Reason: Hot air is lighter than the cold air.
             11.  In liquid, the molecules are ……………..packed and ………… to move.                          1
             12.  Fluids means ……………and ………………. who have tendency to flow.                              1
             13.     a)  Explain the formation of Sea Breeze.                                           2+1
                     b)  Draw the diagram showing Land breeze formation.
   1   2