7/25/2019 Electric Energy Assignment
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Class-X Assignment1
Assignment
Electric Energy, Power and House Hold Circuits
1. (a)State three factors which determine the quantity of heat
produced in a
conductor.
(b)An electric appliance having a resistance of 150 is operated
at 240V.
Calculate the energy consumed by the appliance in 5minutes in SI
system.
2. (a)What do you understand by the term earthing?
(b)Which part of the electrical appliance is earthed and
why?
(c)Calculate the heat energy given out by the filament of a bulb
in 10seconds,
when its resistance is 4and p.d. across its terminals is24V.
3. (a)Explain, why the wires used as leads of an electric heater
are thicker than
the leads of a table fan.
(b)
Calculate the resistance of a nichrome wire which will bring 250
g of wate
at 0C to its boiling point in10minutes, when the current flowing
through
the wire is 5A.
7/25/2019 Electric Energy Assignment
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Class-X Assignment2
4. (a)Two bulbs of 100W and 15W are connected to 240V - A.C.
mains in series.
It is found that 15W bulb glows brightly. Explain the
observation very
clearly.
(b)
An electric oven of resistance 20draws a current of 10A. It
works 2hour
daily. Calculate the cost of energy for a single day if energy
costs Rs. 2.75
per standard commercial unit
Answers
1. (b) 115200 J 2.(c) 1440 J 3.(b) 7 5. (b) Rs. 11.00
