Electricity 2.0 Flashcards
(30 cards)
What is the symbol and units for current
I, amps
What is the symbol and units for power
P, watts
What is the symbol and units for voltage
V, volts
What is the symbol and units for resistance
R, ohms
What is direct current
Current flows in one direction ONLY
What is alternating current
Current is CONTINUOUSLY changing direction
What is the point of a fuse
to melt and break a circuit when the current passing through is too high and to ISOLATE the appliance from the mains
What does RCD stand for
Residual current device
What does a RCD do
It detects the difference between the current in the live and neutral wires
What does it mean if there is a difference between the current flowing in the live and neutral wires
there is a fault and the current is flowing through some other part of the appliance
What will a RCD do if it detects a difference between the live and neutral wire
break (stop the circuit)
Which does a fuse or a circuit breaker act faster
circuit breaker
What is the current like in a series circuit
the same all the way round
What is the current like in a parallel circuit
main current splits and goes through both branches
What is the voltage like in a series circuit
The bulbs share the voltage
What is the voltage like in a parallel circuit
each bulb gets the full voltage
In a parallel circuit if one branch had two bulbs and the other had one which branch would have the higher current
The branch with only one bulb
What is a diode
A diode only allows current to flow through it in one direction
What way does a diode have to face for current to flow
Forward-biased
What is it called when the diode doesn’t let current flow
Reversed-biased
What is a conductor
Conductors allow electrons to flow through them e.g. metals
What is an insulator
They impede the flow of electrons
How does the temperature of the filament of a light bulb effect the resistance
As the temperature increase so does the resistance
What is a variable resistor
A resistor that has an adjustable resistance
