Current in a Magnetic Field Flashcards
A current-carrying conductor in a magnetic field will experience a force that is:
- Perpendicular to the current
- Perpendicular to the magnetic field
If the conductor is parallel to the magnetic field…
…no force will be produced.
What is Fleming’s left-hand rule?
F - Force
B - Magnetic field (flux)
I - Current (Conventional current, positive to negative)
How would you demonstrate the force on a current-carrying conductor?
Place a conducting wire between two magnetic poles, pass a current through the wire, the wire will move down, reverse the current and the wire will move up.
What is a commutator?
A device that allows current reversal.
What are uses of a commutator?
- Electrical motors
- d.c. motors
- Moving-coil meters and loudspeakers
What is magnetic flux density?
The magnitude of magnetic field strength. Denoted by B and measured in T (Teslas).
What is an ampere?
One ampere (1A) is the constant current when you have two straight infinitely long parallel conductors a meter apart, in a vacuum, with negligible cross-section, with a force produced between them of 2×10-⁷Nm-¹.
How would you demonstrate magnetic force between two current carrying conductors?
Set up a circuit with a power source and tinfoil in a horse shoe shape. When you apply current, it will travel down one side of the tinfoil and up the other side. This will have the effect of two opposite direction currents in parallel conductors. This will cause a magnetic repulsion.
