the citadel or high fortified area of an ancient Greek city. the Acropolis, the citadel of Athens and the site of the Parthenon.
Electromagnets are used in a number of everyday devices. One useful characteristic of an electromagnet is the fact that you can vary its magnetic force by changing the amount and direction of the current going through the coils or windings around it.ummary. Electromagnets are used in a number of devices, such as loudspeakers and tape recorders. Some electromagnets can be very strong and its power can be readily turned off and on, such as in junk yard electromagnets and electromagnetic locks.
Best Answer: There are many of them used in a car including the starter solenoid. They have an electromagnet which pulls a steel cylinder in when you connect your battery to the electromagnet coil wire.So the mechanical motion of the cylinder can be used to close switch contacts or valves of various sorts.The electric door locks are another example of their use.hey have an electromagnet which pulls a steel cylinder in when you connect your battery to the electromagnet coil wire. So the mechanical motion of the cylinder can be used to close switch contacts or valves of various sorts.