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Objective questions:
                   1.  SI unit of heat energy ---------.
                   2.  Calorie is the unit of --------- quantity?
                           2
                   3.  H= I Rt joule=--------- calorie .
                   4.  Melting point of tungsten filament -------.
                   5.  Electric fuse wire is made of ----- & ----.

               Assertion: Electric heating devices are made of alloys.
               Reason:  Alloys does not oxidize at higher temperature.

               Subjective questions:


               1. Why are copper or aluminium wires generally used for electrical
               transmission and distribution purposes?

               2.  How heat is produced when electric current is passed through a conductor?


               3. Define Joule’s law.


               4. How does electric heater,iron and water heater work on heating effect of current?


               5. Why does filament of an electric bulb is made up of tungsten?



               6. Why electric fuse in the electric circuit melts when large current flows in the
               circuit?



               7. Why does electric bulb glows when electric current flows through filament of the
               bulb?


               Numericals:



                   1.  A 12 V battery connected to a bulb drives a current of 1.5 A through it. Find
                       the energy supplied by the battery in 10 minutes.
                   2.  An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat
                       developed in 30 seconds.
                   3.  An electric heater rated 1200 W operates 2 hour per day. Find the cost of the
                       energy required to operate it for 30 days at Rs 5.00 per unit.
                   4.  An electric heater rated 600 W operates 6 hours per day. Find the cost to
                       operate it for 30 days at Rs. 3.00 per unit. A-324/-
                   5.  An electric kettle of 2 kW works for 2 h daily. Calculate the (a) energy
                       consumed in SI and commercial units (b) cost of running it in the month of
                       June at the rate of `3.00 per unit.A-14400000J,4 units,360/-
                   6.  In a household, 5 tube lights of 40 W each are used for 5 hours and an
                       electric press of 500 W for 4 hour everyday. Calculate the total energy
                       consumed by the tube lights and press in a month of 30 days.A-90KWh
                   7.  The rating of an electric heater is 1100 W, 220 V. Calculate its resistance and
                       the energy consumed in kWh in the month of November, if the heater is used
                       daily for four hours at the rated voltage.A-44ohm,132KWh
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