The power of an electric bulb is 100W. It is connected to a 110V power supply. The resistance of the electric bulb will be?
Correct answer: B. 121Ω
- A. 11Ω
- B. 121Ω
- C. 20Ω
- D. 200Ω
Explanation
From the power formula P = V²/R, we can rearrange to find the resistance: R = V²/P. R = (110 V)² / 100 W = 12100 / 100 = 121 Ω.
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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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