A Nichrome heater dissipates 550 W when the applied potential difference is 110 V and the wire temperature is We have to calculate the amount of water that would be dissipated if the wire temperature were held at by immersion in a bath of cooling oil. We may assume that the applied potential difference remains the same and for Nichrome at is .

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We recall that relation between power, P, voltage, V, and the resistance, R, is

The resistance of the Nichrome wire which dissipates 550 W at 110 V will be

Assuming that variation of temperature is given by the relation

We find the resistance of the wire at from its value at We have

The dissipation rate of Joule heat at by the Nichrome wire at a potential difference of 110 V will be