1. Circuit Equations and how to solve them

2. Agenda 1 2 3 4 Quick Review Circuit Equations
Solving Circuit Equations 3
Sample Problems 4

3. HOW TO SOLVE CIRCUIT EQUATIONS
Circuits Review
Now that we're familiar with the vocabulary of circuits, the parts of a circuit and how to draw them, we need to figure out how to calculate
the values.
Recall, there are two types of circuits we’ll be investigating: Series and Parallel.
CIRCUIT EQUATIONS
Now , let’s cover how to apply the terms we learned to actual circuits
HOW TO SOLVE CIRCUIT EQUATIONS

4. V Series Circuits Voltage
Finding the Voltage of a Series Circuit is very straight forward. You simply add all the voltages across each of the loads in the circuit together
Now, let’s figure it out.

5. Finding the Series Formula for Voltage
VT = V1 + V2 + V3 + V

6. V I Series Circuits Voltage
Finding the Voltage of a Series Circuit is very straight forward. You simply add all the voltages across each of the loads in the circuit together I
Current
Current in a Series Circuit is the same throughout, because the electricity can only travel in a straight line around the circuit.
Now, let’s find the formula

7. Finding the Series Formula for Current
IT = I1 = I2 = I3 = I4

8. V I R Series Circuits Voltage
Finding the Voltage of a Series Circuit is very straight forward. You simply add all the voltages across each of the loads in the circuit together I
Current
Current in a Series Circuit is the same throughout, because the electricity can only travel in a straight line around the circuit. R
Resistance
Resistance in a Series Circuit is simply found by adding up the value of each resistor
Now, let’s show this equation

9. Finding the Series Formula for Resistance
RT = R1+ R2 +R3 +R4....

10. V I R ST Series Circuits Voltage
Finding the Voltage of a Series Circuit is very straight forward. You simply add all the voltages across each of the loads in the circuit together I
Current
Current in a Series Circuit is the same throughout, because the electricity can only travel in a straight line around the circuit. R
Resistance
Resistance in a Series Circuit is simply found by adding up the value of each resistor ST
Now, let’s Solve a problem using Thinking Skills

11. ARTIFICIAL INTELLIGENCE
Solve for the Circuit, given the information included
ARTIFICIAL INTELLIGENCE
Find the following for the circuit
1) Total Resistance
2) Total Current
3) Voltage at Each Resistor (Recall V = I x R)
4) The Power for Each Resistor

12. Break Time
Stand up and Stretch.
Quick Washroom and Drink Breaks

13. V Parallel Circuits Voltage
Voltage in a Parallel Circuit is divided up evenly, so all branches have the same push on the electrons
Now, let’s figure it out.

14. Finding the Parallel Formula for Voltage
VT = V1 = V2 = V3 = V

15. V I Parallel Circuits Voltage
Voltage in a Parallel Circuit is divided up equally, so all branches have the same push on the electrons I
Current
Unlike a Series Circuit, in a Parallel Circuit the electricity that travels through one branch is different than the electricity that travels through another. So to find the total current, you must add all the individual currents together.
Now, let’s find the formula

16. Finding the Parallel Formula for Current
IT = I1 + I2 + I3 + I4

17. V I R Parallel Circuits Voltage
Finding the Voltage of a Series Circuit is very straight forward. You simply add all the voltages across each of the loads in the circuit together I
Current
Unlike a Series Circuit, in a Parallel Circuit the electricity that travels through one branch is different than the electricity that travels through another. So, to find the total current you must add all the individual currents together. R
Resistance
Resistance in parallel circuits is MUCH more difficult to figure out through reasoning. The individual resistors are each on different branches. So electricity traveling through each branch will find different resistance, and so we must represent the resistance of each single resistor as being divided by 1
Now, let’s show this equation

18. Finding the Parallel Formula for Resistance

19. V I R ST Parallel Circuits Voltage
Voltage in a Parallel Circuit is divided up evenly, so all branches have the same push on the electrons I
Current
Unlike a Series Circuit, in a Parallel Circuit the electricity that travels through one branch is different than the electricity that travels through another. So, to find the total current you must add all the individual currents together. . R
Resistance
Resistance in a Parallel Circuit is MUCH more difficult to figure out through reasoning. The individual resistors are each on different branches. So, electricity traveling through each branch will find different resistance. As we’ve learned, electricity will always take the path of least resistance, and so we must represent the resistance of each single resistor as being divided by 1. ST
Now, let’s Solve a problem using Thinking Skills and the formulas

20. ARTIFICIAL INTELLIGENCE
Solve for the Circuit, given the information included
ARTIFICIAL INTELLIGENCE
Find the following for the circuit
1) Voltage at Each Resistor
2) Total Current
3) Total Resistance
4) The Power for Each Resistor

21. HOW TO SOLVE CIRCUIT EQUATIONS
Circuits Review
Now that we're familiar with the vocabulary of circuits, the parts of a circuit and how to draw them, we need to figure out how to calculate
the values.
Circuit Diagrams and Formulas can be used to Solve problems using Thinking skills
Recall, there are two types of circuits we’ll be investigating: Series and Parallel.
CIRCUIT EQUATIONS
Now , let’s cover how to apply the terms we learned to actual circuits
HOW TO SOLVE CIRCUIT EQUATIONS

22. THE BRAIN IS AN INTELLIGENT CIRCUIT
In many ways, the human brain is like a complex circuit.
It sends electrical signals from one point to another
It receives ‘feedback’ which controls how much signal is used, like a switch
It increases and decreases Resistance depending on the input from the system
It can return information (signals) back to the original source in a ‘feedback loop’

23. Our Brains also send electrical charges from one point to another
But our electrical signals are caused by chemical reactions and the movement of ions, not friction or induction

24. Biological Circuits
The nerves in your body send electrical signals from different sensory organs to enable your brain to make the right decisions
Your brain makes decisions, like a computer, based on the ‘input’ from your senses
Your body can only respond by muscle contraction to move your body or digest food or talk to your friends right now.
Your Muscles Contract and move your Body
Your brain weighs the information and sends electrical signals back to your body to cause your muscles to contract
Your Brain Reads the Road Map
Your body receives feedback from the system to help it continue to respond, and like a circuit, it continues to go round and round.
Then your Muscles and Senses send feedback and the cycle continues

25. HOW TO SOLVE CIRCUIT EQUATIONS
Circuits Review
Now that we're familiar with the vocabulary of circuits, the parts of a circuit and how to draw them, we need to figure out how to calculate
the values.
Circuit Diagrams and Formulas can be used to Solve problems using Thinking skills
Recall, there are two types of circuits we’ll be investigating: Series and Parallel.
CIRCUIT EQUATIONS
Several similarities can be shown between a circuit and the human brain
Now , let’s cover how to apply the terms we learned to actual circuits
HOW TO SOLVE CIRCUIT EQUATIONS

26. Fluorescent Lights How are fluorescent lights different than
Conventional
lightbulbs?

27. Fluorescent Lights These lamps heat up Mercury to vapour form which
it causes it to
ionize.
This causes it to emit light, but the light is in the UV range so it can’t
be seen by the human eye.

28. Fluorescent Lights The glass on the inside of the bulb
is covered in a phosphor, which picks up the UV
light given off by
the Mercury
vapour and then
releases it as visible light.

29. Fluorescent Lights
This is the same technology used to make Compact Fluorescent Lightbulbs (CFL)
Canada switched over to CFL from common incandescent lightbulbs a few years ago

30. Light Emitting Diode
But now, the newest technology embraced by society is the Light Emitting Diode (LED).
This light provides several advantages to the fluorescent lightbulb, including less toxic compounds, longer lifespans, roughly 50,000 hours, which is 50 times longer than incandescent lightbulbs and 8-10 times longer than CFLs.

31. AC vs DC
AC stands for Alternating Current, which means that the electricity travels through one direction, completes the circuit, and then electricity travels through the other way.
This is the kind of circuit you would see in most household/building wiring.
DC stands for Direct Current, which means that the electricity only travels in one direction, losing electrons in one spot and gaining them in another. This is the kind of circuit you would see in most battery powered objects, and that’s why they need to be replaced.

32. Now that you understand how electricity works and can be used, it’s time to think of questions that we can ask about it.

33. The Characteristics of Electricity
Please review your notes and feel free to come in during your lunch to get extra help.
Questions?
You should start studying every day for about 15 – 20 min, looking over your notes and making sure you understand all the ideas and problems being shown.
How should I study?
Study groups are one of the most effective ways to help learn. Working in small groups will allow you to ask questions and make sure you can explain the ideas.
Study Groups
The test for this unit will be a week today! Please make sure you’re ready for it!
When is the Test?