Lenz Law (1 Viewer)

[umz93]

Hi
My question is based on question 20 from the hsc physics paper 2003.
If a solenoid is connected to a circuit and a magnet was moved next to the solenoid, the solenoid would obviously move to the left due to opposing magnetic fields.
However would the solenoid move back to the right after it moves to the left?
Thanks

 

[ohexploitable]

Yes.

the the motion of the magnet is stopped.

There is no longer relative motion between the conductor (solenoid) and the magnetic field (bar magnet), therefore, the induced emf returns to nil, no current means no magnetic field is generated to oppose the bar magnet.

 

[umz93]

Thanks
But since it is connected in a circuit doesnt that mean that it there will be current flowing through the solenoid?

 

[ohexploitable]

Thanks
But since it is connected in a circuit doesnt that mean that it there will be current flowing through the solenoid?

This will only be true if the solenoid is a superconductor (i.e. no resistance), when there is no emf any current will be quickly dissipated due to the solenoid's resistance.

NOTE: I'm half pulling this out of my ass.