have you got the energy Flashcards
(15 cards)
VOLTAGE
The difference in electrical potential between two points. It is the pushing power in an electrical circuit.
CURRENT
the flow of electricity (flow of electrons)
It is a flow of electric charge, in circuits this charge is carried by moving electrons.
RESSISTANCE
A measure of him much a material tries to stop electricity passing through it.
Ohm Law
The relationship between current, voltage and resistance can be summarised by ohms law.
what does ohm’s law state
voltage= current x resistance
or
V=IR
constant current
if the resistance of a component doubles, then the voltage drop and energy lost will double too
constant supply of voltage
if the ressistance of a component doubles, then only half the current will flow through it
constant resistance
If the current through a component doubles, then the voltage drop and energy lost will double too
using ohm’s law
V= IR I= V divided by R R= V divided by I
units of measurement
current= amps voltage= volts resistance= ohms
series circuit
The components are attached one after the other in a continuous chain which starts and ends at the power source.
The electric current in the circuit must flow through each resistor one after the other.
There is only one path for the charged electrons to take
if a globe is broken in the circuit then no other globes will work
The voltage supplied is split between two globes but the current passing through is the same
parallel circuit
This type of connection allows different paths for the current to flow.
The charged electrons flowing in this type of circuit reach the splitting point in the wires and can then flow along each path.
if a globe is broken the other globe will remain lit as there is still a circuit through which current may flow
the voltage used by each globe is the same but the current is split between each branch.
difference between series and parallel
In a series circuit the current is the same the whole way through where as in a parallel circuit the current splits to flow along each parallel path.
what do you need in a circuit
power source e.g. battery light bulb switch wires voltmetre ammeter
ohms law- when number of cells increases:
the value of I increases
the value of v increases
