Voltage

• Predict how current will change when resistance of the circuit is fixed and voltage is varied.
• Predict how current will change when voltage of the circuit is fixed and resistance is varied.

• Determine the variables that affect the strength and direction of the electric field for a static arrangement of charges.
• Investigate the variables that affect the strength of the electrostatic potential (voltage).
• Explain equipotential lines and compare them to the electric field lines.
• For an arrangement of static charges, predict the electric field lines. Verify the prediction using vector addition.

Most of us use electricity every day in many different ways so it is important that we understand the dangers, or hazards, associated with electricity and we know how to use it safely.

When a circuit is connected and complete, charge can move through the circuit. Charge will not move unless there is a reason, a force to drive it around the circuit. Think of it as though charge is at rest and some- thing has to push it along. This means that work needs to be done to make charge move. A force acts on the charges, doing work, to make them move. The force is provided by the battery in the circuit.