A battery of emf 10 V and internal resistance 2 ohm is connected to a resistor. If the current is 0.5 A, the resistance is
Q1. A battery of emf 10 V and internal resistance 2 ohm is connected to a resistor. If the current is 0.5 A, the resistance is
Answer: 18 ohm
Explanation: Using I = E / (R + r), where E = 10, I = 0.5, r = 2, we get 0.5 = 10 / (R + 2), hence R + 2 = 20, R = 18 ohm