03. Electrical Circuits
Outcomes:
Recall that Electric current is a flow of electric charge. The size of the electric current is the rate of flow of electric charge.
Use the equation: I = Q/t
Recall that the potential difference (voltage) between two points in an electric circuit is the work done (energy transferred) per coulomb of charge that passes between the points
Use the equation: V = E/Q
Recall how to calculate the potential difference provided by cells connected in series (depending on the direction in which they are connected)
Activity - recalling circuit diagrams and symbols
Activity
Look at the two circuits on the right:
What is the difference?
How will they behave differently?
if you take out a bulb
if you add another bulb in?
Try it, use the circuit kits to make both of these circuits.
For each one draw the circuit diagram in your book.
The DC Circuit Builder simulation can help.
Activity - open the Investigating Circuits Task sheet, follow the instructions and answer all the questions fully in your exercise book.
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Voltage and Current
After watching the demonstration of how to measure current and voltage using a multimeter you can investigate.
The current in a series circuit......
The voltage in a parallel circuit....
Measure the current with an ammeter to find out what happens in series and parallel circuits at different points
Connect cells the wrong way round. What happens? Why?
Add cells into the circuit, describe what happens when you do this.
Measure the voltage with a voltmeter to find out what happens in series and parallel circuits.
The current (I) is the flow of charge:
I = Q/t Q - charge (coulombs)
I - current (amps)
Make a notecard of this
The potential difference (V) is the energy difference between two points in a circuit.
This energy is carried by the charge.
V = E /Q V - voltage (volts)
E - energy (joules)
