Current Electricity Charging Discharging Of Capacitors Question 479
Question: There are two electric bulbs of 40 W and 100 W. Which one will be brighter when first connected in series and then in parallel,
[MP PET 1993]
Options:
A) 40 W in series and 100 W in parallel
B) 100 W in series and 40 W in parallel
C) 40 W both in series and parallel will be uniform
D) 100 W both in series and parallel will be uniform
Show Answer
Answer:
Correct Answer: A
Solution:
$ \frac{R _{1}}{R _{2}}=\frac{P _{2}}{P _{1}}=\frac{100}{40}=\frac{5}{2} $ . Resistance of 40 W bulb is $ \frac{5}{2} $ times than 100 W. In series, $ P=i^{2}R $ and in parallel, $ P=\frac{V^{2}}{R} $ . So 40 W in series and 100 W in parallel will glow brighter.
BETA
