Question Detail
Question
A battery of emf 4V and internal resistance of 2 Ohms is joined to a resistor of 8 Ohms. Calculate the terminal potential difference.
Correct Answer
Option A is the correct answer.
Detailed Explanation
Given:Electromotive force (E) = 4 VInternal resistance (r) = 2 ΩExternal resistance (R) = 8 ΩFirst, calculate the total current (I) flowing in the circuit using Ohm's Law for the entire circuit:I = E / (R + r)I = 4 V / (8 Ω + 2 Ω) = 4 V / 10 Ω = 0.4 AThe terminal potential difference (V_terminal) can be calculated in two ways:1. V_terminal = E - Ir (EMF minus voltage drop across internal resistance)V_terminal = 4 V - (0.4 A * 2 Ω) = 4 V - 0.8 V = 3.2 V2. V_terminal = IR (Voltage across the external resistor)V_terminal = 0.4 A * 8 Ω = 3.2 VBoth methods yield the same result.
Hint
First, calculate the total current flowing through the circuit. Then, use the formula for terminal voltage, which accounts for the internal resistance of the battery.