Unit 5: Electricity Chapter 12: Electric Circuits 12.2 Current and Voltage 12.3 Resistance and Ohm's Law

SWBAT explain how electricity travels though a circuit. Objective Date: Feb. 9 SWBAT explain how electricity travels though a circuit.

12.1 Investigation: Measuring Voltage and Current Key Question: How do you measure voltage and current in electric circuits? Objectives: Build simple circuits and draw circuit diagrams. Measure current and voltage in a battery. Identify electrical conductors and insulators.

Electricity Electricity is the flow of charged particles that carry energy from one place to another. The flow of the electric charge is called electric current.

Electric current Electric current is similar in some ways to a current of water. Like electric current, water current can carry energy and do work. A waterwheel turns when a current of water exerts a force on it.

Electric Circuits An electric circuit is a complete path through which electric current travels. A good example of a circuit is the one found in an electric toaster.

Electric Circuits Wires in electric circuits are similar in some ways to pipes and hoses that carry water. How are pipes and circuits different? Electric current enters the house on a supply wire and leaves on a return wire. The big difference between wires and water pipes is that you cannot get electricity to leave a wire the way water can leave a pipe. If you cut a water pipe, the water flows out. If you cut a wire, the electric current stops immediately.

Natural circuits These are some examples of natural electrical circuits: The nerves in your body The tail of an electric eel Lightning carries electric current between clouds and the ground.

Electric Circuits When drawing a circuit diagram, symbols are used to represent each part of the circuit.

Electric Circuits Electrical symbols are quicker and easier to draw than realistic pictures of the components. Stop: Period 8 1/8

Electric current Electric current is caused by moving electric charge. Electric current comes from the motion of electrons. current #8 – Period 3

Resistors A resistor is an electrical device that uses the energy carried by electric current in a specific way. Any electrical device that uses energy can be shown with a resistor symbol. STOP Period 4 : 1/8

Current in a circuit Current only flows when there is a complete and unbroken path, or a closed circuit. Flipping a switch to the “off” position creates an open circuit by making a break in the wire.

Wipeboard Activity http://www.learningcircuits.co.uk/flashmain.htm Handout Print Out Available

Practice Quiz What is the flow of electricity called? ________________ What is the complete electric path called? ______________________ If the lights of off in your house, then the circuit must be ______________.

12.1 Investigation: Measuring Voltage and Current Key Question: How do you measure voltage and current in electric circuits? Objectives: Build simple circuits and draw circuit diagrams. Measure current and voltage in a battery. Identify electrical conductors and insulators.