NEET2026PhysicsChapterActual
A storage battery of emf 10 V and internal resistance 2 is being charged by a 30 V DC supply using a series resistor of 3 as shown in the given figure. The terminal voltage of the battery during the charging process is:
Options
- A12 V
- B2 V
- C22 V
- D18 V
Correct answer
D. 18 V
Step-by-step solution
The net electromotive force (EMF) in the circuit is the difference between the two opposing voltage sources: E_ net = 30 V - 10 V = 20 V The total resistance in the series circuit is: R_ total = 3 + 2 = 5 The current I flowing through the circuit is: I = E_ net R_ total = 20 5 = 4 A During the charging process, the current flows into the positive terminal of the 10 V battery. The terminal voltage V across the battery is given by: V = E + Ir Substituting the given values: V = 10 + (4 2) V = 10 + 8 = 18 V Answer: 18