the motor effect

• When a current flows through a wire...

  a magnetic field is produced around it
• The force can be increased by increasing the...

  current or by increasing the strength of the magnetic field
• The force is greatest when the wire is perpendicular...

  to the magnetic field
• It is zero when the wire is...

  Parallel to the magnetic field lines
• The direction of the fore is always at right angles to the wire and...

  The magnetic field lines and the direction is reversed if the c or mg is
• In an electric speaker, you can control the speed of...

  an electric current and reverse its turning direction by reversing the current
• The coil spins because q force acts on each side of...

  the coil due to the motor effect and the force on one side is is in the opposite d of the force on the other
• The split ring commutator reverses the current round the...

  coil every half turn of the coil, meaning the coil is pushed in the same direction every 1/2 turn
• In a loudspeaker, a coil vibrates when...

  alternating current passes through the coil
• Each time the current changes its direction...

  the force reverses its direction
• As it is constantly forced back and forth, the motion...

  Makes the diaphragm vibrate so loudly so sound waves are created
• Wire moves out of the page

  Use the left hand rule to predict the movement of the wire

  
• Side B

  Which side of the coil experiences a force into the screen?

  
• Side D

  Which side of the coil experiences a force out of the screen?

  
• Side C


  Which side experiences no force?

  
• Motor forced to turn, acts as a generator

  When Electric cars brake they do this to charge their battery. KERs system in F1