Voltage and Current

Voltage

The energy given to electrons that makes them move around the circuit

Current

The rate of flow of charge

Charge

The charge flow in one second when the current is one amp

How do you calculate the number of electrons passed a certain point in a given time period?

• Calculate the overall charge: Q = It

• Divide the overall charge by the charge of a single electron

How does the power source move charge around a circuit?

The power sources does work to move charge around the circuit

Potential difference

The work done in moving a unit charge between two specific points

OR

p.d. is 1 volt when 1 joule of energy is used to move 1 coulomb of charge through a component

Describe what happens in a circuit

• The positive terminal has a potential 1.5V higher than the negative

• Negative charges are attracted to the positive terminal and pass through the bulb

• Their potential energy is converted to heat

• When charges reach the positive terminal they have no potential energy left

• The battery moves the electrons to the higher potential (expending chemical energy to do so)

• Electrons continue to move around the circuit until they can no longer be promoted to the higher potential