Current Electricity Charging Discharging Of Capacitors Question 131

[AIIMS 2005]

Options:

A) $ R _{1}=R _{2}=R _{3} $

B) $ R _{2}=R _{3} $ and $ R _{1}=4R _{2} $

C) $ R _{2}=R _{3} $ and $ R _{1}=\frac{1}{4}R _{2} $

D) $ R _{1}=R _{2}+R _{3} $

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Answer:

Correct Answer: C

Solution:

As the voltage in $ R _{2} $ and $ R _{3} $ is same therefore, according to, $ H=\frac{V^{2}}{R}.t, $

$ R _{2}=R _{3} $ Also the energy in all resistance is same. \ $ i^{2}R _{1}t=i _{1}^{2}R _{2}t $ Using $ i _{1}=\frac{R _{3}}{R _{2}+R _{3}}i=\frac{R _{3}}{R _{3}+R _{3}}i=\frac{1}{2}i $ Thus $ i^{2}R _{1}t=\frac{i^{2}}{4}R _{2}t $ or, $ R _{1}=\frac{R _{2}}{4} $