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Motion. Electricity can produce motion!. A. Electrical energy & motion. If a wire with a current running through it produces a magnetic field. . Then why would it not be possible to have a magnet move a wire with a current? Magnets can move magnets, right?
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Motion Electricity can produce motion!
A. Electrical energy & motion • If a wire with a current running through it produces a magnetic field. • . Then why would it not be possible to have a magnet move a wire with a current? Magnets can move magnets, right? • 2. the ability to move object over a distance = energy. • energy associated with current = elect. energy. • energy due to movement = mechanical • energy transformation – a wire with current placed in magn. field, electrical energy – mechanical energy!
Wire with current in magnetic field moves the wire • Fleming’s Left hand rule
B. Galvanometers • 1. used to measure small currents. • If a wire is in a loop, one side is opposite the other as far as current direction. If you put this inside two permanent magnets, one wire will go up, the other down, moving ½ turn. After this, it will stop moving.
Electric Motors • Wires inside galvanometers move ½ turn. What if we could move a full turn? • Motor - device using electricity to turn an axle. Electrical– mechanical energy. • In motor, direction of current is reversed just as loop or armature, gets to the vertical position. (The side that moved up on left, now moves down on right .
Parts of a Motor • Most armatures have hundreds of loops wrapped around a ferromagnetic material, increasing the strength of motor. Most large electric motors use electromagnets to increase magnetic field strength. • Commutator (ring split in half) repeatedly reverses the flow of current through the armature. When armature rotates, commutator rotates also and slides past two “brushes.” Because the brushes conduct the current, changing brushes reverses the current and the armature spins continuously!
