Current Electricity - Result Question 80
85. Two electric bulbs, one of $200 V, 40 W$ and other of $200 V, 100 W$ are connected in a domestic circuit. Then
[2000]
(a) they have equal resistance
(b) the resistance of $40 W$ bulb is more than $100 W$ bulb
(c) the resistance of $100 W$ bulb is more than $40 W$ bulb
(d) they have equal current through them
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Answer:
Correct Answer: 85. (b)
Solution:
(b) $\quad R_1=\frac{V^{2}}{P_1}=\frac{200 \times 200}{40}=1000 \Omega$
$R_2=\frac{V^{2}}{P_2}=\frac{200 \times 200}{100}=400 \Omega$
$\therefore R_1$ (for $.40 W)>R_2$ (for $100 W$ )