Page 38 - CHAPTER-1 (Electricity)
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CHAPTER 1
ELECTRICITY
Checkpoint-7
1. A current of 2 A passing through conductor produces 80 J of
heat in 10 seconds. The resistance of the conductor is
(a) 0.5Ω (b) 2Ω
(c) 4Ω (d) 20Ω
2. An expression for the rate of heat generated, if a current of I
ampere flows through a resistance of R , is.
2
2
(a) I Rt (b) I R
2
(c) V R (d) I R
3. The amount of heat that will be produced in a resistor when a
current is passed through it can be calculated using.
(a) Faraday’s Law (b) Kirchhoff’s Law
(c) Laplace’s Law (d)Joule’s Law
(ii) Practical Applications of the Heating Effect of Electric Current
Although the heating effect of electric current cause undesirable loss
of electrical energy still there are some useful applications of it. Some
of them are given below:
a. Electric Bulb:
It has a filament made up of tungsten. So, most of the power taken is
dissipated as heat and some part of the power is converted into light.
Tungsten is one of the chosen metals because it has a high resistivity
and a high melting point.
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