what happens if you move a wire up through a magnetic field, why?
a potential difference is induced across the ends of the wire as the wire experiences a change in magnetic field
what happens when the wire stops moving and why?
the potential difference is lost as nothing is changing
how to increase induced potential difference and current?
- use stronger magnets, generating a stronger magnetic field
- move the wire or magnets more quickly through magnetic field
- shape the wire into the coil
- greater number of turns on this coil, the greater the induced potential difference and current
what creates the potential difference?
change in magnetic field that the wire experiences as it moves through it
what happens when we change direction of wire moving through field (up/down) and why?
direction of potential difference swaps direction (alternating potential difference) as wire experiences a change in direction of magnetic field
what happens if we join the two ends of wire together?
- forms a complete circuit
- so induced potential difference would generate a current
what is needed for a pd to be induced?
- a change in magnetic field
- so wire needs to cut through lines perpendicular, not move parallel
moving a magnet in and out of a solenoid
- will induce a pd across the wire
- current will only flow if its a closed circuit
the generator effect definition
- the induction of a potential difference in a wire which is experiencing a change in magnetic field
what does an induced current generate?
a magnetic field that opposes the original change
two ways to create a pd
- moving a magnet in a coil of wire
- moving a wire in a magnetic field
how to change direction of induced potential / current?
- move magnet in opposite direction
- reverse polarity of the magnet
why is the induced potential difference across the coil alternating?
magnet changes direction
explain why a current was detected when the wire was moved upwards
- wire cuts through magnetic field
- a pd was induced
- as it was part of a complete surface
