The potential difference between the two end terminals of an electric heater is 220 V and the current through it is 0.5 A. What would be the current through the heater if the potential difference across the terminals of the heater is reduced to 120 V ?

  1. A. 1.0 A
  2. B. 0.5 A
  3. C. 0.27 A ✓
  4. D. 0.7 A

Correct Answer: C. 0.27 A

Explanation

Resistance R = \frac{V}{I} = \frac{220}{0.5} = 440 \ \Omega. When voltage is 120 V, the new current I = \frac{V}{R} = \frac{120}{440} \approx 0.27 \text{ A}.

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