Lesson 3: Current and voltage in an electrical circuit

Open Ended

Current is the number of electrons flowing through a single point in a circuit.

Predict whether the amount of current will increase, decrease or stay the same as it flows around a simple circuit.

Open Ended

Voltage is a measure of the push that drives electrons between two points in a circuit – for example, between the two terminals of a battery.

Predict whether you would expect the same voltage across the different components of the circuit.

Draw

Record your current and voltage readings from the simulations. (write the answer on the diagram)

Open Ended

Describe how current and voltage vary across the electrical circuit. Does this match your prediction?

Open Ended

Compare your voltage measurement across the battery to the voltage across the other components in the circuit.

Open Ended

In terms of the effect of resistance on electrons, explain why the voltage "drops" over components in the circuit.

Open Ended

Your classmate is trying to measure the current in the circuit shown to the left.

Predict what the current in the circuit will be.

The voltage and resistance of each component is the same as the circuit you created.

Draw

Use Ohm's law to calculate the resistance of each resistor and the light bulbs.

Draw

The circuit shown to the right contains two light bulbs, two resistors and a heater.

The current across the circuit is 0.75 A.

Calculate the voltage across the heater.