In the circuit shown, the potential drop across the 6 Ω resistor is 12 V. The emf of the ideal battery is:
Correct answer: C. 24 V
- A. 8 V
- B. 16 V
- C. 24 V
- D. 32 V
Explanation
To solve this problem, we use Ohm's Law, V = IR. Given that the potential drop across the 6 Ω resistor is 12 V, we can calculate the current through it: I = V/R = 12 V / 6 Ω = 2 A. Assuming this is the only resistor in the circuit, and since the battery is ideal (no internal resistance), the emf of the battery must equal the potential drop required to maintain this current, which is 24 V. Thus, Option C is correct. All other options either underestimate or overestimate the necessary emf based on the given potential drop across the resistor.
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About Current Electricity
Steady current relates charge flow to potential difference, resistance and resistivity, including how temperature changes a conductor's resistance. Sources with internal resistance have terminal voltage below their emf when delivering current, and maximum power output occurs under a specific load condition rather than at zero resistance.
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