JEE MainPhysicsElectromagnetic Induction
A circuit consists of three parallel branches connected between two main nodes. The left branch contains a 20 V battery (positive terminal upwards) in series with a 2 resistor. The middle branch contains a 4 resistor, an inductor L , and a switch. The right branch contains an 8 V battery (positive terminal upwards) in series with a 4 resistor. The current through the 20 V battery just after closing the switch is ____
Correct answer
2
Step-by-step solution
Just after closing the switch (at t = 0 ), the inductor opposes any change in current and behaves as an open circuit. Therefore, no current flows through the middle branch, and it can be ignored for the initial current calculation. The circuit reduces to a single loop containing the left branch and the right branch. The two batteries are connected in opposition (both positive terminals are connected to the top node). Applying Kirchhoff's Voltage Law (KVL) around the outer loop, assuming current I flows upwards in t