ME6 - The motor effect Flashcards
How does a motor effect happen?
When you put a current carrying wire in a magnetic field (causes the wire to move)
Why does the wire move?
It is because charged particles moving through a magnetic field will experience a force as long as they’re not moving parallel to the field lines
To experience a full force what does the wire have to be at?
90 degrees to the magnetic field (wont work if the wire runs along the magnetic field)
What direction does the force always act towards?
The same direction relative to the magnetic field of the magnets and the direction of the current in the wire (north-south poles)
The direction of the force depends on what?
- The direction of the magnetic field
- Direction of the current
What is a good way showing the direction of a force?
Apply a current to a set of rails inside a horseshoe magnet. A bar is placed on the rails which completes the circuit - this generates a force that rolls the bar along the rails
What does the magnitude of the force increase?
Th strength of the magnetic field
How else does the force increase?
The amount of current flowing through the conductor
What happens if you reverse the current or magnetic field?
It also reverse the direction of the magnetic field
What does flemings left hand rule tell you?
Which way the force acts
What do the thumb, first finger and second finger represent?
Thumb - Motion (force)
First finger - Field
Second finger - Current
How do you use flemings left hand rule?
Using your left hand point your first finger in the direction of the field and your second finger in the direction of the current. Your thumb will then point in the direction of the force (motion)
A thin strip of aluminium foil held between the poles of a strong magnet
When the switch is closed the aluminium foil moves. Explain way
The magnetic field due to the current in the foil interacts with the permanent magnetic field of magnet, causing a force on the foil so, the foil moves.
