A soft-iron rod is pulled away from the magnet that magnetized it. What happens to the rod?
A coil of wire is wound around a big iron nail and connected to a battery. The nail's tip now picks up a chain of paperclips. Disconnect one battery wire, and the paperclips drop at once.
The coil around the nail is a solenoid, and the nail fills its middle. A piece filling the middle of a coil is called the coil's core. This core is soft iron: a material that magnetizes easily and loses its magnetism the moment the cause is removed.
A solenoid wound on a soft-iron core is called an electromagnet.
Close the switch, and the current flows: the electromagnet makes a magnetic field, and the paperclips jump up to the nail. Open the switch, and the current stops: the field is gone, and the paperclips fall.
Which parts make up an electromagnet?
The current through an electromagnet is switched off. What happens to its field?
A door latch holds shut while a current flows through its coil on a soft-iron core. The current stops. What happens to the coil's field?
An electromagnet's field is on only while the current flows.
The field disappears as soon as the current stops.
A student winds a solenoid with an empty middle, with no core. Is it an electromagnet?
An electromagnet is a solenoid wound on a soft-iron core.
This coil has no core.
No. Without a soft-iron core it is just a solenoid.
What is a solenoid wound on a soft-iron core called?
A student winds a coil around an iron bolt and wires the coil to a battery. The bolt picks up steel screws. The student then disconnects the battery. What happens?
Which feature shows a lifting magnet is an electromagnet rather than a permanent magnet?
Which statement about an electromagnet is correct?