Download Circuits Simulation

Circuits Simulation
We are going to look at voltage and current in circuits using a computer simulation. This allows us to
‘see’ a little more of what is happening in the circuit.
First you need to load the circuit simulation software. Your teacher will explain how to do this.
Now start to construct your first circuit:

Drag a cell onto the page from the bar on the right.

Now add a bulb.

Join the components using sections of wire, as shown.
Good, now you’re ready to start taking measurements.
Record each result in the table:
Measure:

The voltage produced by the cell
Voltage across cell

The voltage used by the bulb
Voltage across bulb

The current on both sides of the circuit
LHS
RHS
Current
You should have seen that all the voltage from the cell was used by the bulb. In reality the wire also has
some resistance, so it will use some of the voltage too. Let’s see how this affects the circuit:

Open the ‘advanced options’ by clicking on the button on the
right hand side of the screen

Move the slider labelled wire resistivity a small distance to
the right

Now repeat your readings
Voltage across cell
Voltage across bulb
LHS
Current
RHS
1. Has the voltage produced by the cell changed?
Yes / No
Explain why you think this is ………………………………………………………………………..
………………………………………………………………………………………………………..
2. Has the voltage used by the bulb changed?
Yes / No
Explain why you think this is ………………………………………………………………………..
………………………………………………………………………………………………………..
3. Has the current in the circuit changed?
Yes / No
Explain why you think this is ………………………………………………………………………..
………………………………………………………………………………………………………..
Now move the slider for the “wire resistivity” back to the far left.
We are going to add a second bulb to our circuit, but first let’s try to make some predictions!
What do you think will happen to the charges in the circuit when we add a second bulb?
……………………………………………………………………………………………
How will this affect our measurement of current?
……………………………………………………………………………………………
How much voltage will there be across each of the bulbs?
…………………………………………………………………………………………….
Now add the bulb and record your results below.
Voltage across cell
Current in the circuit
Bulb 1
Bulb 2
Voltage across bulbs
Were your predictions correct…?
Yes / No