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Physics Help!!!! A soldering iron uses an electric current in a wire to heat the tip?


johnsmith89
(@johnsmith89)
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A soldering iron uses an electric current in a wire to heat the tip. A transformer with 100 turns on the secondary coil provides 51 W at an rms voltage of 28 V. Assume that the soldering iron is plugged into a 120 V outlet. What is the resistance of the wire in the iron? How many turns are in the primary coil? What is the current in the primary coil?


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Tom (admin)
(@tom-soldering)
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"What is the resistance of the wire in the iron?"

P = V^2/R. You have P and V.

 

"How many turns are in the primary coil?"

Ratio of turns = ratio of voltages = 120:28

 

That is, x/100 = 120/28

 

"What is the current in the primary coil?"

P = I * V and you have P and V.


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johnsmith89
(@johnsmith89)
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@tom-soldering thanks!


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