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Question 26.63: A 2.0 kW heater element from a dryer has a length of 80 cm. ......

A 2.0 kW heater element from a dryer has a length of 80 cm. If a 10 cm section is removed, what power is used by the now shortened element at 120 V?

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Combining Eq. 26-28 with Eq. 26-16 demonstrates that the power is inversely proportional to the length (when the voltage is held constant, as in this case). Thus, a new length equal to 7/8 of its original value leads to

R=\rho \frac{L}{A},       (26-16)

P=\frac{V^2}{R}       (resistive dissipation).      (26-28)

P=\frac{8}{7}(2.0 \, kW )=2.4 \,kW .

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