A 10 ohm resistor has a 14.14 V peak drop across it. What power is dissipated?
- 19.99 W.
- 10 W.
- 1.414 W.
Explanation
Peak voltage 14.14 V gives RMS = 14.14/sqrt 2 = 10 V. Power dissipated is V_rms^2/R = 10^2/10 = 10 W. Using the peak voltage directly would wrongly give about 20 W, which is the common error reflected in the 19.99 W distractor.
MridulDev asking:
how?
Community Comments (2)
D
dimky Posts: 514 24.08.2014 / 11:14
Since it mentions peak, it is AC.
Always use RMS voltage when calculating power.
RMS voltage = peak voltage / 1.414 = that 14.14 / 1.414 = 10V
Power = V^2/ R = 10^2 / 10 = 100 / 10 = 10W
Always use RMS voltage when calculating power.
RMS voltage = peak voltage / 1.414 = that 14.14 / 1.414 = 10V
Power = V^2/ R = 10^2 / 10 = 100 / 10 = 10W
M
MridulDev Posts: 48 24.08.2014 / 12:47
thank you
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