P2 cir
Current
a measure of the flow of electrons around a circuit
Amperes, amps, or 'A' are the units of
Current
Potential Difference
the force driving the flow of electrons around a circuit
In 'conventional current', we say that the electrons flow from
Positive terminal ➔ negative terminal
Resistance
everything that resists or opposes the flow of electrons in a circuit
Voltage, volts, and 'V', are all used to refer to
Potential differnece
Ohms (Ω) are the units of
Resistance
Current (or 'conventional current') flows from
Positive terminal ➔ negative terminal
Charge
is a measure of the total current that flowed within a period of time
formula for charge is
charge=current×time
A light emitting diode will
Emit light when current flows through it
Only allow current to flow in one direction
statements about ammeters
They are added to a circuit in series
They measure current
statements about voltmeters are true
They are added to a circuit in parallel
They measure potential difference
In a series circuit, the potential difference of the battery is
Shared across all of the components
_____ circuits only have a single loop
Series
_____ circuits have more than one loop
Parallel
a series circuit, the potential difference of the battery is
Shared across all of the components
In a series circuit, the current is
The same everywhere in the circuit
In a series circuit, the total resistance is ________ the sum of the individual resistances of each component
Equal to
In a series circuit, components with a greater resistance will always have a ________ share of the voltage
Greater
The total current is _____ between all of the parallel loops
Shared
Energy Equ
Energy (E) = Power (P) x Time (t)
Energy Equ
Energy (E) = Voltage (V) x Current (I) x Time (t)
Energy Equ
Energy (E) = Charge (Q) x Voltage (V)
Power Equ
Power (P) = Current (I) x Voltage (V)
Power Equ
Power = Current2 x Resistance
Fossil fuel and nuclear power stations work by generating ______ _____
! Thermal energy
This is used to turn _____ into steam which can then rise and turn turbines
Water
The ______ energy of the moving turbines can be converted to _____ energy, which is finally sent out across the national grid
! Kinetic
! Electrical
formula for electric power is
power=voltage×current
symbol formula for electric power is
P=IV
When transmitting electricity, a ________ current generates lots of wasted heat
High
Step-up transformers are used to
Increase the voltage and decrease the current
Step-down transformers are used to
Decrease the voltage and increase the current
The ____ energy of the moving turbines can be converted to _____ energy, which is finally sent out across the national grid
! Kinetic
! Electrical
The formula for electric power is
power=voltage×current
When transmitting electricity, a ________ current generates lots of wasted heat
High
Step-up transformers are used to
Increase the voltage and decrease the current
Step-down transformers are used to
Decrease the voltage and increase the current
The electric power is transmitted via the national grid at ______ current which minimises power loss
Low
Which type of current periodically reverses its direction
Alternating current
When charge always flows around a circuit in the same direction, we call it
Direct current
Alternating current is caused by
an alternating potential difference
Direct current is supplied by
Batteries
Cells
The role of an oscilloscope is
Display how voltage changes with time
Name the three wires that are normally present in UK plugs
Live wire
Neutral wire
Earth wire
Wires are made of _____ and coated in a layer of insulating _____
! Copper
! Plastic
Which wire prevents the electrical casing from becoming live
Earth wire
Which wire supplies the current to the appliance
Live wire
Which wire completes the circuit, allowing current to flow
Neutral wire
One risk in electric circuits is a surge in ________
The sudden increase in ______ can damage the appliance, cause a fire, or give an electric shock
Current
Which of the following safety features are used to protect against surges in current
Fuses
Circuit breakers
_______ have a thin wire which melts and breaks the circuit when the current is too _____
The _____ of a fuse is the current that will cause the fuse to break the circuit
! Fuses
! High
! Rating
Static electricity is
the build up of charge on insulating materials