Investigating Induced Current in Circular Coils

[Neophyte7]

If I have a top view of two circular coils of conducting wire lying on a flat surface, what is the direciton of induced current that appears in the smaller coil when the switch in the larger coil is closed?

I'm trying to figure out:
1.) which direction the induced current would flow through the smaller coil
2.) how long it would flow: forever, or only for a short time.

I've attached a picture of the wires for clarification.

I'm not sure how to solve this. I know that induced current in a loop occurs only when the magnetic field through that loop changes. I'm assuming that when the switch is closed a current will run counterclockwise around the larger loop, but I don't know if this is a valid assumption, or what that does for the smaller loop. Can soemone help please?

Thank you.

 

[Fightfish]

Can't see the diagram now, but the idea is basically to use Lenz's Law, that the direction of the induced current in the smaller loop will flow in the direction that would create an induced magnetic field which opposes the change in magnetic flux linkage through it i.e. in the likes of N against N and S against S in a simplistic analysis in this case.

 

[tomcue]

I can provide some insight into your questions about induced current in circular coils. The direction of the induced current in the smaller coil will depend on the direction of the changing magnetic field created by the larger coil. This is known as Faraday's law of induction, which states that an induced current will flow in a direction that opposes the change in the magnetic field.

In your scenario, when the switch in the larger coil is closed, a current will indeed run counterclockwise around the larger loop. This will create a changing magnetic field that will induce a current in the smaller coil. The direction of this induced current will be clockwise, as it will oppose the counterclockwise current in the larger coil.

As for the duration of the induced current, it will only flow for a short time, as the changing magnetic field will only be present while the switch is being closed. Once the current in the larger coil stabilizes, the induced current in the smaller coil will also stop flowing.

I hope this helps to clarify your questions about induced current in circular coils. Remember to always consider the direction of the changing magnetic field when determining the direction of the induced current.