JEE MainPhysicsCurrent Electricity
An ideal DC voltage source of V volts is connected to a circuit through a switch. The circuit consists of a 12 resistor connected in parallel with a second branch. The second branch contains a 2 resistor connected in series with a parallel combination of two sub-branches: one sub-branch has a 10 resistor, and the other sub-branch has an uncharged capacitor C in series with a 2.5 resistor. The switch is closed at t =
Correct answer
2
Step-by-step solution
At t = 0 , the uncharged capacitor acts as a short circuit. The second branch consists of the 2 resistor in series with the parallel combination of the 10 and 2.5 resistors. The equivalent resistance of this parallel pair is: R_ p0 = 10 2.5 10 + 2.5 = 25 12.5 = 2 The total resistance of the second branch at t = 0 is: R_ branch2, 0 = 2 + 2 = 4 The total equivalent resistance of the circuit at t = 0 is the parallel combination of the 12 resistor and the 4 branch: R₀ = 12 4 12 + 4 = 48 16 = 3 The initial current is I₀