A 100 W, 200V bulb is connected to a 160 V supply. The actual power consumption would be:
Correct answer: A. 64 W
- A. 64 W
- B. 100 W
- C. 72 W
- D. 90 W
Explanation
First, find the bulb's resistance from its rating: R = V²/P = (200V)² / 100W = 400 Ω. Now, calculate the actual power consumed with the new voltage: P' = (V')²/R = (160V)² / 400Ω = 64 W.
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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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