Current Electricity Charging Discharging Of Capacitors Question 480
Question: Two resistances $ R _{1} $ and $ R _{2} $ when connected in series and parallel with 120 V line, power consumed will be 25 W and 100 W respectively. Then the ratio of power consumed by $ R _{1} $ to that consumed by $ R _{2} $ will be
[EAMCET 1983]
Options:
A) 1 : 1
B) 1 : 2
C) 2 : 1
D) 1 : 4
Show Answer
Answer:
Correct Answer: A
Solution:
$ P=\frac{V^{2}}{R} $
Therefore $ \frac{P _{P}}{P _{S}}=\frac{R _{S}}{R _{P}}=\frac{(R _{1}+R _{2})}{R _{1}R _{2}/(R _{1}+R _{2})}=\frac{{{(R _{1}+R _{2})}^{2}}}{R _{1},R _{2}} $
Therefore $ \frac{100}{25}=\frac{{{(R _{1}+R _{2})}^{2}}}{R _{1}R _{2}} $
Therefore $ \frac{R _{1}}{R _{2}}=\frac{1}{1} $
BETA
