Electricity Flashcards
what is the definition of emf
a voltage where the charge is gaining energy
(maintains the potential energy difference across the ends of the circuit)
what is potential difference
the difference between two ends of the circuit.
as the work done per unit positive charge
what is current
the flow of charge
which way do electrons flow in a circuit
from the negative pole to the positive pole of the cell
what is resistance
the components of the circuit, a measure of the opposition to current flow in an electrical circuit.
how do you calculate emf in a series circuit
Total emf = sum of individual emf
how to calculate the emf in the parallel circuit
the emf is the same as the emf in the single cell
what is a electric current
a flow of charged particles
what is used to measure current,
what is the SI unit of current
ammeter
ampere (A)
what is the SI unit of charge
coloumb
what is a coloumb
the amount of charge that passes through a point in a circuit
what happens to the energy so it can flow through a circuit
electrical potential energy of the battery => kinetic energy of charge
what are the two conditions in order for the charge to flow in the circuit
1) the circuit must be closed
2) there must be a source of potential energy=> kinetic energy ( o be able to move through the circuit)
what is the potential difference
the difference in electric potential energy that is transferred per unit charge
what is the SI unit of potential difference
volt (v)
what is a voltmeter
measures potential difference (in volts)
connected in parallel
what is the conventional current
the direction of positive flow of positive charge to negative
what is a resistance
resistance of a conductor is the materials opposition to the flow of charge
what is the SI unit for resistance
ohms
what is an emf
the total amount of electrical energy that it (battery) supplies per unit charge passing through it
what type of resistance does a flat battery have
high internal resistance
what type of resistance does a full battery have
low internal resistance
what does a parallel circuit do to current
it divides the current
what are the factors affecting resistance of a conductor
1) CROSS - sectional area
wide = easier(less resistance) / narrow = difficult
2) LENGTH - how long the conductor is
long=harder (more resistance)/ short= easier
3) TEMPERATURE - Increase in resistance= increase in resistance
4) TYPE OF METAL(metallic composition)
what is the principle of conservation of charge
it states that the net charge of an isolated system remains constant during any physical process
what is a magnet
a magnet is an object which has opposite magnetic poles at each end
what are the three magnetic metals
iron
cobalt
nickel
what are the poles of a magnet called
south and north pole
what happens when a magnet is broken into half
it creates two magnets
what is a permanent magnet
example
its a magnet that remains (keeps) its magnetism
bar magnets
what is a temporary magnet
example
it’s a magnet that does not retain its magnetism
electromagnets
why are electromagnets tempomporary magnets
they lose their magnetism when electricity is turned off
what is a magnetic field
a region in space in which a magnet/ferromagnetic material will experience a force which is magnetic in nature
what is ferromagnet
alloy
a
what are field lines
show the direction of the force that an iron filling would experience at a particular point in the field
which poles attract
opposite poles attract
which poles repel
same poles repel
which pole is a terminate
which pole is an originate
North
south
from which direction does the force go
from north to south
what is magnetic declination
check pg 93
