GEOLOGY

Detailed explanation-1: -Answer. A semiconductor should be the answer since a semiconductor will only let a certain amount of electric charge flow through.

Detailed explanation-2: -The main advantage of an electromagnet over a permanent magnet is that the magnetic field can be quickly changed by controlling the amount of electric current in the winding. However, unlike a permanent magnet that needs no power, an electromagnet requires a continuous supply of current to maintain the magnetic field.

Detailed explanation-3: -A switch is the device which controls the flow of current through a circuit.

Detailed explanation-4: -Re: Turning off electromagnet Use a relay. Wire the electromagnet to the relay’s normally closed pins, then run current through the pushbutton switch to the relay coil-when you push the switch, it’ll pull the relay the other way and the electromagnet will shut off.

Detailed explanation-5: -Generators, motors, and transformers. Electric buzzers and bells. Headphones and loudspeakers. Relays and valves. Data storage devices like VCRs, tape recorders, hard discs, etc. Induction cooker. Magnetic locks. MRI machines. More items