Testing & TroubleshootingQuestion 502 of 521
A conductor with 0.2 ohms of resistance carries 15 A. How much power is dissipated as heat in that conductor?
a.3 W
b.75 W
c.0.9 W
d.45 W
Explanation
Power in a resistance is P = I^2 x R = (15 A)^2 x 0.2 ohms = 225 x 0.2 = 45 W. Option a is I x R (a voltage, 3 V), b divides incorrectly, and c uses I x R x 0.3. Excess I^2R heating is why loose or undersized terminations overheat.
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