1. The motor effect - - - - + + + +
When a current carrying wire is placed in a magnetic field,
it will experience a force.
This is called the motor effect. S + - + - + - N + -

2. Magnetic Force on a Current-Carrying Conductor
Graphics from Ted Vittitoe

3. Right hand ‘Slap’ rule
fingers ~ field
Thumb ~ current
Slap – force direction

4. The left-hand motor rule
Note:
Magnetic field direction is from NORTH to SOUTH
Current direction is from PLUS to MINUS

6. The force increases if:
– the strength of the magnetic field is increased
– the current is increased
The direction of the force is reversed if either the direction of the current or the direction of the magnetic field is reversed.
The conductor will not experience a force if it is parallel to the magnetic field.
Motor effect - Fendt

7. Force on an Electric Current in a Magnetic Field
A current-carrying wire in a B-field wire experience a Force

8. dot is coming out of the page
cross is going into the page

9. A Force occurs due to the combination of magnetic fields

10.  + =
neutral point

13. Insert the missing information
Q1. Force direction ?
Q2 Current direction ? N S S N
Q3 N and S poles ?
Q4 Force directions ? N S N S
Note:
means current out of the page
means current into the page

14. Find the magnitude and direction of the current that must flow through the red bar in order to remove the tension from the springs. x
B = .440 T L
L = 62.0 cm
m = 13.0 g