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- Created on: 05-04-17 18:27
- The rate of flow of charge
- Symbol I
- Measured in amperes ( A )
- Normally a flow of electrons in metals
- Or flow of ions in electrolytes
- Base SI unit of electric current
- Symbol (A)
- Defined as the current flowing in two parallel wires in a vacuum 1m apart such that there is an attractive force of 2 x 10 -7 N per metre length of wire between them
One type of electric charge, attract negative repel other positives
A type of electric charge such that it repels other negative charge and attracts positive charge.
- The derived SI unit of electric charge.
- 1 coulomb of electric charge passes a point each second when there is a current of one amp
- 1 coulomb = 1 amp x second
- Physical property (symbol of q or Q)
- Positive or negative
- Measured in coulombs or as a relative charge
- An atom that has either lost or gained electrons
- Has a net charge
- A simplified measurement of the electric charge of a particle or object
- Measured in multiples of the elementary charge (q or e)
- The availabilty of some quantities only in certain discrete values
- Examples are elementary charge
- A model used to describe electric current in a circuit
- Travels from positive to negative
- An electron in a metal that is not bound by an atom and is free to move.
- AKA a delocalised electron
- A liquid containing ions that are free to move and so conduct electricity
- An ionic compound dissolved in a liquid
- This forms an electrolyte
A positively charged ion attracted to a cathode. (Which are negatively charged)
A negatively charged ion attracted to an anode.
Cathode and Anode
Cathode - a negatively charged electrode
Anode - a positively charged electrode
- A device used to measure electric current
- Placed in series in a circuit and ideally has zero resistance
- Property of a component calculated by divided the potential difference across it by the current in it.
- Symbol R, unit ohm
- Defined as the energy transferred from electrical to other forms per unit charge
Conservation of charge
- States electric charge cannot be created or destroyed
- Total charge in any interaction is the same before and after said interaction
Kirchhoff's First Law
- At any point at a circuit the current entering is the same as the current leaving
- Electrical charge is conserved
- The number of free electrons per cubic metre of material.
- Symbol n, unit 1/m-3
- A material with a lower number density than a typical conductor.
- Number density typically of order 10 to the 17 1/m3
Mean Drift Velocity
- The average velocity of electrons as they move through a wire
- Symbol v, units metres per second