1. THE CHARACTERISTICS OF ELECTRICITY  Electric Current & Voltage
SNC1D PHYSICS
THE CHARACTERISTICS OF ELECTRICITY
 Electric Current & Voltage

2. Parts of an Electric Circuit
A source of electrical energy:
‑ electrical outlets
‑ biological cells
‑ dry cells
- electromagnetism
‑ solar cells
- Ect.

3. Parts of an Electric Circuit
An electrical load:
A device which converts electrical energy
into another form of energy
(light, heat, motion, etc.)
- a light bulb
- a motor
- a toaster

4. Parts of an Electric Circuit
A device to control the electric current:
- switch
- circuit breaker
- control dial

5. Parts of an Electric Circuit
Electrical conductors for connectors:
‑ usually a metal wire used to connect the
other parts of the circuit.
(the wires are usually covered with an
insulating material to ensure that the
current flows only in the circuit)

6. Electric Circuit Symbols - Matching
Dry cell
Battery
Wire
Switch
Light Bulb
Resistor
Voltmeter
Ammeter

7. 1DPHYS - Electric Current
For any electrical device to operate, there must be a __________ of electrons. The rate at which electrons flow past a specific point in a circuit is called _________________. To better understand the concept of electric current, consider a waterfall.
September 18, 2018
1DPHYS - Electric Current

8. 1DPHYS - Electric Current
ELECTRIC CURRENT (I)
rate at which electrons flow past a specific point in a circuit
SI unit is ampere (A)
September 18, 2018
1DPHYS - Electric Current

9. 1DPHYS - Electric Current
Measuring Current
In order to measure the current flowing through the different loads of a circuit an ______________________ must be connected in series with the load. For example, to measure the current through the light bulb in the circuit below, you must connect the ammeter in series with the light bulb. This ensures that all of the electrons that flow through the lamp will also flow through the ammeter.
September 18, 2018
1DPHYS - Electric Current

10. 1DPHYS - Electric Current
Measuring Current
AMMETER
device used to measure current
must be connected in series with the load
circuit symbol is
September 18, 2018
1DPHYS - Electric Current

11. Measuring Current – MC Cards!
PRACTICE A student connected an ammeter as shown. Did the student connect the ammeter correctly? a) Yes b) No – it is connected in parallel instead of series
September 18, 2018
1DPHYS - Electric Current

12. 1DPHYS - Electric Current
What do you think?
Why is it dangerous to try to help someone who is experiencing an electric shock? What you should do if you wish to help the person? if you were to help you would get shocked as well – turn off the power (if possible) and call 911
September 18, 2018
1DPHYS - Electric Current

13. A Model for Electric Potential Energy
For centuries people have used the energy of falling water to push waterwheels. This is possible because water above the wheel has more gravitational potential energy than it does below the wheel. _____________________________________is the energy stored in an object.
September 18, 2018
1DPHYS - Potential Difference

14. A Model for Electric Potential Energy
As water falls, some of this ____________ is used to spin the waterwheel. To keep the wheel spinning you need a steady supply of falling water such as a fast-flowing stream. If this is not available, a pump can be used to push the water up to its original position. As the water is pumped to its original position, its _______________________also increases to its original amount.
September 18, 2018
1DPHYS - Potential Difference

15. Electric Potential Energy & Potential Difference
Similarly, electrons leave the _________________ terminal of the battery with high ___________________ which is used to operate the motor. As a result, the electrons return to the positive terminal of the battery with ___________________. Once inside the battery, chemical reactions “re-energize” the electrons and send them out the negative terminal again. In this way, the battery acts like the __________.
September 18, 2018
1DPHYS - Potential Difference

16. Electric Potential Energy & Potential Difference
NOTE! The difference in electric potential energy between two points in a circuit is called the _____________________or _____________(V). The SI unit for potential difference is the __________ and the symbol is V. It is this difference that causes current to flow in a closed circuit.
September 18, 2018
1DPHYS - Potential Difference

17. Electric Potential Energy & Potential Difference
POTENTIAL DIFFERENCE (V)
difference in electric potential between two points in a circuit
also called voltage
SI unit is volts (V)
September 18, 2018
1DPHYS - Potential Difference

18. Measuring Potential Difference
The potential difference between two points in a circuit is measured with a __________________. Unlike an ammeter, a voltmeter must be connected in _______________ with the load or energy source. The reason for this is that voltage is relative to __________________________. There is always a _____________in voltage across a load or energy source.
September 18, 2018
1DPHYS - Potential Difference

19. Measuring Potential Difference
VOLTMETER
device used to measure potential difference
must be connected in parallel with the load or energy source
circuit symbol is
September 18, 2018
1DPHYS - Potential Difference

20.  Check Your Learning – MC Cards
A student connected a voltmeter into a circuit as shown. Is this the correct way to connect a voltmeter? Explain. a) Yes b) No – it is connected in series – it should be connected in parallel instead
September 18, 2018
1DPHYS - Potential Difference

21. 1DPHYS - Potential Difference
 Homework
Read 11.2 (pg ). Complete Learning Check (pg. 451), #1-3. Complete Review Questions (pg. 454), #1, 2, 4, 7.
September 18, 2018
1DPHYS - Potential Difference