A copper wire loop is contructed so that its radius, r, can change. It is held n
ID: 2262604 • Letter: A
Question
A copper wire loop is contructed so that its radius, r, can change. It is held near a solenoid that has a constant current through it.
We know that if the radius of the loop were increasing, there would be an induced current through the wire in a clockwise direction.
Explain the direction of the induced current by considering the magnetic force that is exerted on the charge in the wire of the loop.
A copper wire loop is contructed so that its radius, r, can change. It is held near a solenoid that has a constant current through it. We know that if the radius of the loop were increasing, there would be an induced current through the wire in a clockwise direction. Explain the direction of the induced current by considering the magnetic force that is exerted on the charge in the wire of the loop.Explanation / Answer
For part a, recall Lenz' law:
Even though we're not really working with vectors, the negative is included to indicate that the EMF works to oppose the change. If the loop is getting bigger, then the magnetic flux through the loop is increasing, and thus there will be an induced EMF. The induced EMF will form a magnetic field pointing against the magnetic field as to prevent the magnetic flux from increasing. For part b, consider a magnetic field pointing out of the page and a ring of wire that is increasing in size in the plane of the page. Since the material that composes the wire is moving with the wire as it gets bigger, that means that the individual free electrons will have a velocity pointing radially outward as the ring gets bigger. Recall now the equation for the Lorentz force.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.