electricty Flashcards
What is Ohm’s law?
Ohm’s law is the formula that shows the relationship between voltage, current and resistance.
What is the ‘current’ in a circuit?
the amount of energy carriers passing a particular point
It is measured in Amperes (A)
Also stands for ‘I’ in OHMS LAW
What is the ‘voltage’ in a circuit?
the amount of energy that the current is carrying; the potential difference (or the difference in electrical energy) between two points
It is measured in volts.
Stands for ‘V’ in OHMS LAW.
17
Q
What is the ‘resistance’ in a circuit?
Everything that resists or opposes the flow of electrons in a circuit.
Measured in OHMS.
Srands for ‘R’ in OHMS law.
What are the Three things are required in order to have an electric circuit:
Power supply – this provides the electrical energy needed.
Load – this is what converts or changes the electrical energy into another form.
For example, a globe converts electrical energy into light (and heat), a kettle jug converts the electrical energy into heat.
Conducting pathway – enables the current to flow (or move) around the circuit.
What is a series circuit?
A series circuit is a circuit in which resistors are arranged in a chain, so the current has only one path to take. The current is the same through each resistor. (M)
What is a parallel circuit?
A parallel circuit is defined as one where all components are connected between the same set of electrically common points. The current is different for each pathway. (M)
8
Q
What is a voltmeter?
Measures the voltage in an electrical circuit. You hook up the voltmeter parallel to the resistor.
What is an ammeter?
The ammeter measures the current.
You hook up the ammeter in series to the resistor.
- Can I compare a series circuit to a parallel circuit?
HINT: Think pathways, current, voltage and resistance.
In a series circuit:
* The same current flows through all components in the circuit.
* There is ONE pathway for the current to travel.
* Different potential difference (voltage) exist across each component.
In a parallel circuit:
* Different current flows through each component in the circuit.
* There are multiple pathways for the current to travel.
* The potential difference (voltage) existing across the various component in the circuit is same.
Can I explain why an ammeter and voltmeter need to be connected as shown in the diagram below?
Voltage is the difference in electrical energy between two point so it needs to be connected in PARALLEL to work out the difference in the energy going into the load and what’s coming out. That is, the energy that has been used by the component.
However, current needs to be connected needs to be connected in SERIES so that all energy carriers passing through the load/electrical component also pass through the ammeter.
