Monday, 15 June 2020

induction - Measuring voltage drop from induced current


I'm having trouble connecting voltage drops and induced current. Imagine you have a triangular loop make up off three resistors. You place this loop in a constantly changing magnetic field. This changing magnetic field will cause an EMF and a resulting induced current in the loop.


Now imagine I place a voltmeter across one of the resistors. What does the voltmeter read? $IR$ or $2IR$? If you look at the situation one way, you are measuring the voltage drop across one resistor, so $V$ would equal $IR$. But if you look at in another way, you're also measuring the voltage drop across the other half of the circuit which contains two resistors (hence a voltage drop of $2IR$).


I have tried to model this situation in my schools physics lab and I do see that there is a voltage drop across the resistor so the answer is not "there is no voltage drop". My model wasn't perfect, but it seemed to imply that the voltmeter read $3IR$? How could that be?




No comments:

Post a Comment