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Sino87

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## Homework Statement

A toaster uses a Nichrome heating wire. When the toaster is turned on at 27 deg C, the initial current is 1.50A. A few seconds later, the toaster warms up and the current is now 1.30A. The avg. temp coefficient of resistivity for Nichrome wire is 4.5 x 10 ^ -4 (degree C) ^-1. What is the temperature of the heating wire?

## Homework Equations

Nichrome(alloy) p=100 x 10^-8 ohm*m.

p = po [1 + alpha(T - To)]

To=20 deg C.

alpha=4.5x10^-4 (deg C)^-1

Io=1.50A

I=1.30A

T-?

## The Attempt at a Solution

My attempt.

R = Ro [1 + alpha(T - To)]

R - Ro = alpha(T-To)

R=V/I

T= V(1/I - 1/Io)/alpha + 20

T = 20 + V(227.72)

V = (T-20)/227.92

T = 20 + (T-20/227.12) (227.12)

The answer is 360 deg C btw.

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