Is the Polarity on the Voltmeter Wrong for this Mutual Induction Example?

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The forum discussion centers on the polarity of the voltmeter in a mutual induction example, specifically referencing the images from HyperPhysics on coupled inductors. The user Az questions the voltmeter's indication of negative EMF in relation to the current direction shown in the second and third images. Another participant clarifies that the voltmeter measures the voltage drop across a resistor, which aligns with the current's flow from positive to negative. Az acknowledges the oversight of not recognizing the resistor's presence and confirms that the inductor coil acts as the effective source of current.

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azaharak
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Hi

Is it me, or is the polarity on the voltmeter wrong for this mutual induction example.

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/indmut.html

In particular the 2nd and 3rd images of the first page Coupled Inductors.

I agree with the change in B field and induced current direction, but the current that is drawn in the 2nd image should be consistent with a negative EMF in the voltmeter since current travels from + to -.

Same reasoning in the 3rd image down.

Thanks

Az
 
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I think they are indicating the voltage drop across the resistor, which always goes + to - in the direction of current.
 
Thanks..


For some dumb reason, I didn't see the resistor and was treating the voltmeter as the source.

The inductor coil should be the effective source, and the current flows out of the positive terminal through the load, to the negative terminal.

Thanks again

Az
 

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