[PHYS] Example Question: A 290-W heating coil designed to operate from 110 V is made of Nichrome wire 0.230 mm in diameter. (Assume 𝜌 = 1.50 10-6 Ω · m, and 𝛼 = 4.000 10-4(°C)−1 for Nichrome.)

Example Question

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# Question

A 290-W heating coil designed to operate from 110 V is made of Nichrome wire 0.230 mm in diameter. (Assume 𝜌 = 1.50 * 10^(-6) Ω · m, and 𝛼 = 4.000 * 10^(-4)(°C)^(−1) for Nichrome.)

(a) Assuming the resistivity of the Nichrome remains constant at its 20.0°C value, find the length of wire used.

(b) Now consider the variation of resistivity with temperature. What power is delivered to the coil of part (a) when it is warmed to 1 200°C?

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# Explanation

 

(a) Assuming the resistivity of the Nichrome remains constant at its 20.0°C value, find the length of wire used.

 

(b) Now consider the variation of resistivity with temperature. What power is delivered to the coil of part (a) when it is warmed to 1 200°C?

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