Magnetic Fields

Question 1

Force Equation for force on a wire carrying a current in a magnetic field. (Applied when field lines are all perpendicular)

Answer 1

F = BIL

Question 2

Finding direction of Force?

Answer 2

Flemings left-hand rule

• Thumb = Force (F)
• Pointer finger = Flux density (B)
• Index finger = Current (I)

(This applies for conventional current { for protons} )
(when it comes to electron flow or negative charge flip the direction of index finger)

Question 3

Explain Motor…

Answer 3

• Two magnets creating a magnetic field with a coil of wire in between them.
• typically thousands of turns and loops that are attached to a power supply by a split ring commutator.
• Split ring commutator makes sure the current flips every 1/2 a turn so that it keeps spinning.

Question 4

Dynamo effect:

Answer 4

Similar to the motor effect.
When there is a change in magnetic field/change in flux, then current is induced (split ring commutator is not needed, this just means there is going to be alternating current)