P4 Flashcards
Charge
Measured in coulombs. Can be positive or negative
Current
A flow of charge. It tells us about the rate of flow of charge (how many coulombs of charge pass through a point every second). It is measure in amps.
Ampere
Unit of current (the same as a coulomb per second)
Cell
A store of chemical energy used to drive a current
Conductor
A material that conducts electricity well
Insulator
A material that conducts electricity badly
Electron
Tiny particle that flows around a circuit
Series circuit
One in which there are no branching parts to the circuit
Static Electricity
An isolated imbalance of charge
Circuit breaker
A safety device that stops current flowing if the current is too high. If the current is too large, the electromagnet in the circuit breaker becomes very strong, ans this attracts an iron contact, and causes a gap in the circuit, and makes it stop. It does the same thing as a fuse, but this one can be reset
Fuse
A thin piece of wire (usually encased in a cartridge) that burns through or melts if too much current passes through it. A safety device.
Dischared
when electrons flow from a charged object to the conductor, and makes the charges equal again
Van de Graaff generator
a generator that uses friction to scrape off electrons on to the belt, which are then carried off to the spherical metal cover. The cover is negatively charged, and the electrons stay there as they cannot be conducted through the air. when you touch the generatorm the electrons move onto you. If you are insulated (e.g standing on polystyrene) the electrons can’t go anywhere and make you negatively charged
Equation for current
Current= charge/time I=Q/t
Ammeter
a device that measures electrical current
