Which magnets need electric current for magnetism?

An electromagnet is a magnet that works with electricity. It can be switched on and off. The coils are nearly always made of copper wire because copper is such an excellent electrical conductor. Electromagnets have many uses.Permanent magnets are mainly used in small generators, and they have the advantage that they don't need a power supply. Electric magnets are iron or steel wound with wire. When electricity passes through the wire, the metal becomes magnetic and creates a magnetic field.

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earth's surface is mainly heated by the absorption of infrared radiation from the sun.

evaporation occurs because molecules in liquid water are warmed ( usually by the sun) and vibrate quicker, becoming less dense and rise.

condensation occurs because molecules in water vapor are cooled and therefore vibrate more slowly thus becoming more dense and eventually fall to earth.

lines of equal barometric pressure on a weather map are called: isobars : lines of equal temp on a weather map are called: isotherms.​