# A.C. Circuit (1 Viewer)

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#### frozen7

An electric toaster draws 3A rms current from a 240V, 50Hz source. Calculate the average power and peak value of the instantaneous power to the toaster.

$$P(average) = I (rms) x V (rms) cos \phi$$

Since the power factor is not mentioned in the question. Can the question be solved?

#### berkeman

Mentor
If the power factor isn't given, it probably isn't needed. What would you guess the power factor of a toaster to be? What is the heating mechanism?

#### frozen7

Is it because all the energy become heat so the power factor is equal to one ?

#### berkeman

Mentor
Yeah. The heating element is purely resistive, and the power factor of a resistive circuit is unity. You only get a phase shift between the applied voltage and resulting current if the load is reactive.

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