Ch. 22 - Magnetism

Ch. 22 - Magnetism

II. Uses of Magnetic Fields

(p.628-632) Electromagnet Speaker Motor

A. ElectromagnetElectromagnet

strong, temporary magnet formed when current is passed through a coil of wire surrounding an iron core

acts like a bar magnet when current is on

B. SpeakerSpeaker

electrical energy mechanical energy

wire coil moves back & forth as its magnetic field interacts with the field of a fixed magnet

forced vibration causes the cone to move sound

C. MotorMotor

electrical energy mechanical energy

electromagnet rotates between the poles of a fixed magnet

commutator reverses the poles of the e’magnet

C. Motor

brushes & wires to battery field magnet

armature & commutatorassembled motor