A magnet's N pole is brought near a steel clip. Which pole appears on the clip's near side?
A solenoid with no core hangs over a dish of steel washers, carrying a current. It lifts 2 washers. A soft-iron rod slides into the coil's middle. Same coil, same current. Now it lifts 11 washers.
Only one thing changed: the soft-iron core went in. The coil's field magnetizes the soft-iron core. The magnetized core adds its own field to the coil's. Together they make a far stronger field than the coil alone.
The coil alone still makes a field, a weak one. The current, not the core, is the field's source. The core only strengthens what the coil makes.
The soft-iron core is lifted out of an electromagnet, current unchanged. What happens to the field?
An iron bolt slides into an air-filled, current-carrying coil. What happens to the coil's field?
A soft-iron core slides into a current-carrying coil. What happens to the field's strength?
The coil's field magnetizes the core.
The magnetized core adds its own field to the coil's.
The field gets much stronger.
A technician slides the soft-iron core out of a working electromagnet, leaving the current unchanged. What happens to its field?
Without the core, only the coil's own field is left.
The field gets weaker.
Dev says a current-carrying coil still makes a field with its core removed. Is Dev correct?
Which change makes a working electromagnet weaker?
Two identical coils carry equal currents. One holds a soft-iron core; one is empty. Which lifts more steel pins?
A wooden rod replaces an electromagnet's soft-iron core, same size and current. What happens to the electromagnet's strength?