JEE MainPhysicsCurrent Electricity
In a DC circuit, a battery of unknown voltage V is connected in series with a 2 resistor, which leads to a node A. From node A, the circuit splits into two parallel branches that eventually connect to the negative terminal (ground). The first branch contains a 6 resistor connected directly to ground. The second branch contains a 3 resistor leading to a node C, which then splits into two parallel 6 resistors that reco
Options
- A10 V
- B20 V
- C12 V
- D44 V
Correct answer
B. 20 V
Step-by-step solution
In the steady state, the capacitor acts as an open circuit, so no current flows through the diagonal branch connecting node A and node D. The ammeter at node D measures the total current flowing through the second branch. The equivalent resistance of this second branch (from node A to node D) is the 3 resistor in series with the parallel combination of the two 6 resistors: R₂ = 3 + 6 6 6 + 6 = 3 + 3 = 6 . Since the current through this branch is 2 A , the potential at node A is: V_A = I₂ R₂ = 2 6 = 12 V . The first