SP6a Electricity and circuits Flashcards
What do atoms contain?
.protons +
.neutrons 0
.electrons -
.electron shell
.nucleus
Current?
the rate of flow of electric charge. It is not used up.
When will current flow? (2)
.there is a power supply
.a complete circuit
Conventional current flow?
flows from the positive terminal of the battery to the negative terminal.
Electron flow?
flows from negative terminal of the battery to the positive terminal.
What does a chemical reaction in the battery do?
gives one end of the battery a small positive charge. The other end of the battery is given a small negative charge.
What happens before the switch is turned on?
before the switch is turned on there are charges in the battery. There are charges through all the wires and in the lamp too.
What happens after the switch is turned on?
when the switch is turned on, the battery forces the charges in the wires and the lamp to move.
In the wires, where are charges pushed from and towards?
charges are pushed from one end of the battery, and pulled towards the other end.
What is the flow of charge in a circuit called?
electric current.
What is electric current measured in and how is it measured?
it is measured in amperes (A), using an ammeter, connected in series to measure the current passing through a component.
What is the voltage across a component equal to?
the work done per unit charge.
In a circuit, what is the voltage across the power supply always equal to?
the sum of the rest of the voltages across the rest of the components.
Diffference between series and parallel circuit in relation to voltage.
.series circuit - components divide the available voltage between them
.parallel circuit - components have equal voltage
What is potential difference measured in and how is it measured?
it is measured in volts (V), using a voltmeter, connected in parallel to measure the potential difference across a component.
State differences between parallel and series in relation to potential difference and current.
.parallel - potential difference across components is the same
.series - potential difference is shared between components
.parallel - current at a junction splits
.series - components have the same current
State 3 differences between series and parallel.
.series - one lamp breaks then all the lamps go out
.parallel - one lamp breaks then the others stay on
.series - lamps cannot be switched on and off imdependently
.parallel - lamps in one branch can be switched on and off independently
.series - adding more lamps makes them get dimmer
.parallel - as more lamps are added the brightness stays the same
State 2 similarities between series and parallel.
.voltage pushes free electrons
.electrons flow from negative to positive terminal
