Electricity Flashcards
What is meant by a complete circuit?
In order for a circuit to work it has to be complete, the current has to flow from one side to the other with no gaps
What is a series circuit?
In a series circuit the electrical current flows round in 1 path through each component
What is a parallel circuit?
In parallel the electrical current is able to branch off to reach each component on the board
What happens when more bulbs are added to a series circuit?
When more bulbs are added upin series the light given off gets dimmer (if the bulbs are identical the light given off will be the same)
What happens when 1 bulb breaks in series?
When 1 bulb breaks, the whole circuit is broken it becomes incomplete and the electrical current can’t flow round the circuit
What happens when more bulbs are added in parallel?
When more bulb are added in parallel the light given off will stay the same, there should be no change in brightness
What happens when 1 bulb breaks in parallel?
When 1 bulb breaks the rest will remain on as in parallel the current can branch off and reach a,l bulbs at the same time keeping a complete circuit
-l I- - -l I-
Battery
-lI-
Cell
-o/ o-
Switch
-O-
Bulb
What is an electrical conductor?
An electrical conductor should allow an electric current to flow through it easily
Give 3 examples of an conductor?
Copper, brass and carbon (graphite)
What is an electrical insulator?
An electrical insulator should not allow an electrical current to flow through it at all
Give 3 examples of an insulator
Glass, rubber and silicon
Draw a diagram of a circuit to show the correct positions of an ammeter and a voltmeter
——lI- - -lI——
l l l= walls
A l A= ammeter
l l V= voltmeter
—O——O—— O= bulb
l l
V
Describe electrical current in terms of movement and charges around a circuit
An electrical current is the flow of electrons. Electrons are negatively charged meaning they move round the board from the negative charge in a battery
What is the rule for current in series?
In series the current is the same at all positions round the board
What is the rule for voltage in series?
The sum of voltages across components in series is equal to the voltage drawn from the supply
What is the rule for current parallel?
In parallel branches is equal to the current drawn from the supply
What is the rule for voltage in parallel?
The voltage across components in parallel is the same for each component
What is the function of switches in series?
If there is more than one switch in series, all of them need to be pressed down in order to let the current flow and complete the circuit
What is the function of switches in parallel?
If there is more than one switch in a parallel circuit one (or any) can be closed in order to complete the circuit as the current can branch if and reach other components
What is electrical resistance?
Electrical resistance is the ability of an object to reduce (or oppose) the flow of a current
What is the link between voltage and current for a resistor?
Voltage and current are directly proportional for a resistor.
A graph of V versus I will always be a straight line through the origin
Define R=V/I
Resistance (Ohms)= Voltage (V)/ Current (I)
What is the equation to find out the voltage?
V=IR
