P4 Flashcards
How do you know there’s an electric current in a circuit
If you close the switch the electrons flow out if the cell and around the circuit this is the electronic current
It goes from negative to positive end and once it gets to positive it’s loss energy
What’s the unit for electronic current
Amps (A)
How is current in a series circuit
The same current passes through each component
How is potential difference seen in a series circuit
The total pd of the power supply is shared between the components
How is resistance seen in a series circuit
The total resistance of two (or more) components is equal to the sum of resistance of each component
How is current in a parallel circuit
The bigger the resistance of a component the smaller the current will pass through that component
What’s the potential difference of a parallel circuit
The components in parallel the potential difference across each component is the same
How is resistance in a parallel circuit
Then total resistance of two (or more) components in parallel is less than the resistance of the resistor with the least resistance
What happens to a bulb in a series circuit if there more than one
So 1V tells us 1J of energy’s transferred for each column of charge that’s moving through the circuit
As there is 2 Lanka they can become dimmer which can be explained in pd. As the current is shared between the 2 bulbs doesn’t have to be equally though.
What is resistance
As the current moves electrons collide with atoms in the metal. Electrical energy is transformed into other forms such as thermal
Resistance tells us the pd required to drive a current through a component
What’s the equation for resistance
R(ohms) = v(pd) / I(current)
What does a diode graph look like
In a forward direction, the line curves forward to the y-axis so it’s not directly proportional to the pd.
A diode is a non-onmiconductor, in reverse current is 0 so diodes higher.
What does is an LED light
It is a diode that emits lights when a current passes through it at a forward direction
What is a thermistor
A temperature-dependant resistor and it’s resistance decreases as temperature decreases
