1 John Parkinson © 2 THE AURORA The Aurora Borealis, the Northern Lights and the Aurora Australis, the Southern lights are phenomena resulting from the.

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    01-Jan-2016

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John Parkinson JP THE AURORAThe Aurora Borealis, the Northern Lights and the Aurora Australis, the Southern lights are phenomena resulting from the interaction between Solar Wind and the Earths magnetic field. JP NSLines of magnetic flux, Magnetic flux density, B, measures the strength of the magnetic field.B = number of lines of flux per square metreUNITS are Webers per square metre Wb m-2 or TESLAS (T)B IS A VECTOR QUANTITYJP NSLines of magnetic flux, ATotal magnetic flux through area A is given by: = B A webers, when the area is perpendicular to the field = B A sinJP JP 1820Professor Oersted was demonstrating an experiment for students when he accidentally discovered that a compass needle moved when it was close to a wire connected to a battery.Professor Hans Christian OerstedJP BJP BJP RIGHT HAND GRIP RULE:JP current outwardscurrent inwardsBJP IN turnsIn the middleat the endJP NSInteraction between a magnet and the field due to a currentJP JP FLEMINGS LEFT HAND MOTOR RULEJP FLEMINGS LEFT HAND MOTOR RULEFOREFINGER = FIELDTHUMB = MOTIONSECOND FINGER = CURRENTJP F = B I lWhere l = length of conductor in the fieldJP MOVING COIL METERJP JP NSEVERY TIME THE COIL PASSES THROUGH THE VERTICAL POSITION, THE COMMUTATOR REVERSES THE CURENT IN THE COIL, IN ORDER TO SUSTAIN THE ROTATIONDC MOTORJP LOUDSPEAKERAC signalJP JP Force experienced by a charged particle (charge Q) moving with a velocity, v in a magnetic field of Flux density, B+QParticle travels l metres from A to B in t secondsF = B I lF = B Q vJP +FFTHE FORCE IS ALWAYS PERPENDICULAR TO THE MOTIONTHE PARTICLE MUST MOVE ALONG AN ARC OF A CIRCLE+JP Frequency of Rotation, f+The frequency is independent of the radius and the velocityThis is the principle of the CYCLOTRONJP CYCLOTRON+High frequency square waveJP

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