Current Electricity - Result Question 73
78. When three identical bulbs of 60 watt, 200 volt rating are connected in series to a 200 volt supply, the power drawn by them will be
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======= ####78. When three identical bulbs of 60 watt, 200 volt rating are connected in series to a 200 volt supply, the power drawn by them will be
c3eec34ec6b1fad69db54a20ad4b2dca40c2aa54 (a) 20 watt
(b) 60 watt
(c) 180 watt
(d) 10 watt
[2004]
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Answer:
Correct Answer: 78. (a)
Solution:
- (a) $\frac{1}{P _{\text{eq }}}=\frac{1}{P_1}+\frac{1}{P_2}+\frac{1}{P_3}$ or $\frac{1}{P _{\text{eq }}}=\frac{3}{60}$ $\Rightarrow P _{\text{eq }}=20$ watt.
