Class 51 Magnetic Effect of a Current · Class 51 Magnetic Effect of a Current Author: Rishi Gopie...
Transcript of Class 51 Magnetic Effect of a Current · Class 51 Magnetic Effect of a Current Author: Rishi Gopie...
Electromagnetism Physics Mr Rishi Gopie
Magnetism
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Magnetic Effect of a Current: Electromagnetism
1) Consider the magnetic fields associated with the flow of current: a) in a long , straight conductor
in each case the magnetic field consists of a set of concentric circles
Magnetism
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The right hand grip rule can be used to determine 1) The direction (or sense) of the field lines (i.e. whether clockwise or
anticlockwise) if the current direction is known. 2) The direction of the current if the direction (i.e. sense) of the field lines is
known.
i) In a flat circular coil
ii) In a solenoid
Magnetism
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Inside the solenoid the field lines are close together, parallel and equidistant –
indicating a strong uniform magnetic field.
Outside the solenoid the field lines are further apart and are not parallel and
evenly spaced – indicating a weaker, non-‐uniform field. The external field
resembles that of a bipolar bar magnet and the solenoid itself has a polarity like
that of a bipolar bar magnet and the solenoid itself has a polarity like that of a
bipolar bar magnet.
Introducing a magnetically soft material into the solenoid greatly increases the
strength of its magnetic fields. The material so introduced into the solenoid is
referred to as a cove.
The right hand grip rule can be used to determine
i) The polarity of the solenoid if the current direction is known
ii) The current direction if the polarity (or field line directions) of the
solenoid is known.