IGCSE+ELECTROMAGNETISM

Back to MAGNETISM AND ELECTROMAGNETISM =ELECTROMAGNETISM= 6.8 recall that an electric current in a conductor produces a magnetic field round it

6.9 describe the construction of electromagnets

ELECTROMAGNET: A current-carrying coil of wire (SOLENOID) often wrapped around a soft magnetic core which produces a magnetic field quite like a bar magnet with uniform field lines inside.

6.10 sketch and recognise magnetic field patterns for a straight wire, a flat circular coil and a solenoid when each is carrying a current.

[|FIELD AROUND A STRAIGHT WIRE] Java applet

6.11 appreciate that there is a force on a charged particle when it moves in a magnetic field as long as its motion is not parallel to the field [|DEFLECTION OF ELECTRONS IN A MAGNETIC FIELD] Java applet. WARNING: error in the simulation; the electrons are deflected the wrong way!

6.12 recall that a force is exerted on a current-carrying wire in a magnetic field, and, how this effect is applied in simple d.c. electric motors and loudspeakers

MOTOR EFFECT: A current-carrying wire in a magnetic field experiences a force. This effect is applied in simple DC motors, loudspeakers and ammeters. The force is greater when the field or current are greater.



[|HOW A MOTOR WORKS] Java applet [|PARTS OF THE MOTOR] Passmyexams.co.uk website - also motor effect and LH rule

[|HOW A SPEAKER WORKS] Java applet


 * 6.13 predict the direction of the resulting force when a wire carries a current **
 * perpendicular to a magnetic field **

LEFT HAND (MOTOR) RULE: With the First finger, seCond finger and ThuMb at right angles to each other, we can model respectively Field, Current and Thrust (Motion) on a conductor.


 * 6.14 recall that the force on a current-carrying conductor in a magnetic field increases with the strength of the field and with the current **