1. Electricity 2
objectives

2. Bill Nye video “Electricity”
Crossword

3. Electric Potential Energy
Stored electrical energy
Ex. A battery has stored electrical energy because the electrons have the ability to do work after they leave the battery.

4. Electric Potential Difference
The change in potential energy per coulomb of charge.
Also called voltage
Measured in volts (V)
Measured using a voltmeter

5. Electric Charge
A building up at the negative terminal of a cell/battery which then flows from this terminal as negative charges repel one another.

6. Electrochemical cell & Electric Charge
Two types of electrochemical cells – dry cells (battery in a flashlight) and wet cells (battery in a car)
Both types produce voltage

7. Electrochemical Cell
An electrochemical cell is a device or a mechanism that can either generate electrical energy from a chemical reaction or utilize electrical energy to produce a chemical reaction.

8. Electrochemical cell

10. Electrochemical cell is made of;
2 electrodes usually made of different metals
The electrodes are in an electrolyte, which is a substance that conducts electricity
Dry cell – electrolyte is a paste
Wet cell – electrolyte is a fluid

11. How it Works
The acidic electrolyte attacks the zinc electrode and pulls atoms off the zinc.
But the zinc atoms leave electrons behind on the electrode, and the electrode becomes negatively charged
At the same time, chemical reactions pull electrons off the copper electrode
Therefore the copper electrode has a positive charge. Because there is an opposite charge on each electrode, there is a potential difference (voltage) between the two electrodes.

12. Electric Circuit A complete pathway that allows electrons to flow.
Will transform electrical energy into other forms of energy.

13. Parts of an Electric Circuit

14. Describe the parts of an electric circuit;
Source of electrical energy
Electrical load
Control / switch
conductor

15. Electric Current
The amount of charge passing a given point in a conductor per second.
Measured in amperes (A)
Measured using an ammeter

16. Flow of Electric Current

17. Current Electricity
The continuous flow of charge in a complete circuit.

18. Circuit Diagrams

19. Circuit Diagram Symbols: Page 262
Bulb
Cell
Battery
Wires
Resistors
Ammeter
Voltmeter
Open / closed switch

20. How to Draw a Circuit Diagram

21. Worksheets
Drawing circuit diagrams
How to make light bulbs glow

22. Potential energy is stored energy
In a circuit, the battery stores energy (source of the potential energy). Once it is connected to a light bulb, the electric potential energy is “released”. As the electrons move through the wire inside the bulb, the electrons energy is converted to heat and light energy.

23. Electrical Resistance
Slows down the flow of electrons and converts electrical energy into other forms of energy.
Measured in ohm’s (Ω)
The ratio of the voltage to the current.

24. Factors affecting resistance in a wire
Length
Diameter
Type
temperature

25. Resistors
Used to control current or potential difference in a circuit.

26. Textbook Page 277
Resisters Values Worksheet

27. Ohm’s Law
The mathematical relationship comparing voltage (V), current (I) and resistance (R) V I R

28. Calculate Voltage, Current, & Resistance
Practice Problems Page Worksheets – calculating voltage, current, and resistance.

29. Lab Page