Gcse how does a generator work

When tackling a question on either of them, make sure you are writing about the right one! Diagram showing how the current varies with the position of the coil. A generator looks very similar to a motor, but instead of connecting it to a power supply, the coil is spun by some mechanical process which then produces electricity When a coil is spun in a magnetic field, a voltage is induced between the ends of the coil. As the coil rotates, it cuts through the field lines This induces an EMF between the end of the coil which could then create a current The size of this EMF could be increased by: Turning the coil faster Increasing the strength of the magnetic field Adding more turns to the coil Slip rings, attached to the ends of the coil, transfer the current to metal brushes whilst allowing the coil to rotate freely.

When a conductor cuts through field lines , it induces an EMF. The A. General Physics 1. Thermal Physics 2. The size of the induced voltage can be increased by:. Mains electricity is an AC supply. The voltage it supplies to our homes is about V volts. Generators When a wire is moved in the magnetic field of a generator , the movement, magnetic field and current are all at right angles to each other. Alternator A simple alternator is a type of generator that converts mechanical energy to electrical energy in the form of alternating current An alternator is a rotating coil in a magnetic field connected to commutator rings.

A rectangular coil that is forced to spin in a uniform magnetic field The coil is connected to a centre-reading meter by metal brushes that press on two metal slip rings or commutator rings The slip rings and brushes provide a continuous connection between the coil and the meter When the coil turns in one direction: The pointer defects first one way, then the opposite way, and then back again This is because the coil cuts through the magnetic field lines and a potential difference, and therefore current, is induced in the coil The pointer deflects in both directions because the current in the circuit repeatedly changes direction as the coil spins This is because the induced potential difference in the coil repeatedly changes its direction This continues on as long as the coil keeps turning in the same direction The induced potential difference and the current alternate because they repeatedly change direction A.

Dynamos A dynamo is a direct-current generator A simple dynamo is the same as an alternator except that the dynamo has a split-ring commutator instead of two separate slip rings A dynamo is a rotating coil in a magnetic field connected to a split ring commutator.

As the coil rotates, it cuts through the field lines This induces a potential difference between the end of the coil The split ring commutator changes the connections between the coil and the brushes every half turn in order to keep the current leaving the dynamo in the same direction This happens each time the coil is perpendicular to the magnetic field lines Therefore, the induced potential difference does not reverse its direction as it does in the alternator Instead, it varies from zero to a maximum value twice each cycle of rotation, and never changes polarity positive to negative This means the current is always positive or always negative D.

When tackling a question on either of them, make sure you are writing about the right one! Energy 1. Electricity 2. Particle Model of Matter 3. Atomic Structure 4. Forces 5.