Current Electricity Charging Discharging Of Capacitors Question 435
Question: If $ R _{1} $ and $ R _{2} $ are respectively the filament resistances of a 200 watt bulb and 100 watt bulb designed to operate on the same voltage, then
[NCERT 1980; CPMT 1991, 97]
Options:
A) $ R _{1} $ is two times $ R _{2} $
B) $ R _{2} $ is two times $ R _{1} $
C) $ R _{2} $ is four times $ R _{1} $
D) $ R _{1} $ is four times $ R _{2} $
Show Answer
Answer:
Correct Answer: B
Solution:
$ P\propto \frac{1}{R}\Rightarrow \frac{P _{1}}{P _{2}}=\frac{R _{2}}{R _{1}} $
$ \Rightarrow \frac{200}{100}=\frac{R _{2}}{R _{1}}\Rightarrow R _{2}=2R _{1} $
BETA
