Which statement about a current-carrying solenoid is correct?
A magnet's north pole is pushed toward a coil whose loop is complete. An EMF is induced, and a current flows.
A coil carrying a current is a magnet, with a pole at each face. So which pole does the coil turn toward the approaching magnet?
The coil's near face becomes a north pole. A north face repels the approaching north pole. The coil pushes the magnet back.
Now the magnet is pulled away instead. The coil's near face becomes a south pole. A south face attracts the retreating north pole. The coil pulls the magnet back.
Push the magnet in, and the coil pushes back. Pull it away, and the coil pulls back. The induced current always works against the change.
A magnet approaches a closed coil, and a current is induced. What does the current's magnetic effect do to the approach?
Lenz's law: the induced current flows in the direction whose magnetic effect opposes the change producing it.
The change here is the magnet's approach.
The induced current's magnetic effect opposes the approach. It pushes the magnet back.
A magnet is dragged away from a closed coil. What does the induced current's magnetic effect do?
The change here is the magnet's retreat.
The induced current's magnetic effect opposes that change.
It pulls the magnet back toward the coil, opposing the retreat.
A magnet swings toward a closed coil. What does the induced current's magnetic effect do to the swing?
A magnet is lifted off a closed coil. What does the coil's magnetic effect do to the magnet?
Which rule says the induced current flows in the direction whose magnetic effect opposes the change producing it?
Which statement is Lenz's law?
A magnet swings toward a closed coil, then away, then toward it again. What does the induced current's magnetic effect do across the whole swing?
A magnet falls straight through a closed coil. What does the induced current's magnetic effect do to the falling magnet?