1. Physics 16 General Physics
Direct-Current Circuits
MARLON FLORES SACEDON

2. Electric Current
The flow of current

3. Electric Circuits What is an electric circuit?
An electric circuit is a path in which electrons from a voltage or current source flow. The point where those electrons enter an electrical circuit is called the "source" of electrons. 𝐼 𝐼 𝐼

4. Electric Circuits Two basic circuit connections Series connection +
𝑅 1
𝑅 2
𝑅 3
𝑉 𝑒𝑞
Parallel connection +
𝑅 1
𝑅 2
𝑅 3
𝑉 𝑒𝑞
𝑉 1
𝐼 1
𝐼 𝑇
𝑉 2
𝑉 2
𝑉 3
𝑉 1
𝐼 2
𝐼 1
𝐼 2
𝐼 3
𝐼 𝑇
𝑅 𝑒𝑞
𝑅 𝑒𝑞
𝐼 3
Formulas for simple parallel
𝑉 3
Formulas for simple series
1. Voltage is constant : 𝑉 𝑒𝑞 = 𝑉 1 = 𝑉 2 = 𝑉 3
1. Current is constant: 𝐼 𝑒𝑞 = 𝐼 1 = 𝐼 2 = 𝐼 3
Total current is the sum all point current:
𝐼 𝑒𝑞 = 𝐼 1 + 𝐼 2 + 𝐼 3
Total voltage is the sum all point voltages:
𝑉 𝑒𝑞 = 𝑉 1 + 𝑉 2 + 𝑉 3
3. Total resistance is the sum of reciprocal of all resistance :
1 𝑅 𝑒𝑞 = 1 𝑅 𝑅 𝑅 3
3. Total resistance is the sum of point resistance :
𝑅 𝑒𝑞 = 𝑅 1 + 𝑅 2 + 𝑅 3
For two resistance: 𝑅 𝑒𝑞 = 𝑅 1 𝑅 2 𝑅 1 + 𝑅 2

5. Electric Circuits
Formulas for simple series
1. Current is constant: 𝐼 𝑒𝑞 = 𝐼 1 = 𝐼 2 = 𝐼 3
Total voltage is the sum all point voltages:
𝑉 𝑒𝑞 = 𝑉 1 + 𝑉 2 + 𝑉 3
3. Total resistance is the sum of point resistance :
𝑅 𝑒𝑞 = 𝑅 1 + 𝑅 2 + 𝑅 3
Formulas for simple parallel
1. Voltage is constant : 𝑉 𝑒𝑞 = 𝑉 1 = 𝑉 2 = 𝑉 3
Total current is the sum all point current:
𝐼 𝑒𝑞 = 𝐼 1 + 𝐼 2 + 𝐼 3
3. Total resistance is the sum of reciprocal of all resistance :
1 𝑅 𝑒𝑞 = 1 𝑅 𝑅 𝑅 3
For two resistance: 𝑅 𝑒𝑞 = 𝑅 1 𝑅 2 𝑅 1 + 𝑅 2
Problem 1 Series connection: Calculate the following: Currents 𝐼 1 , 𝐼 2 , and 𝐼 3 and Voltages 𝑉 1 , 𝑉 2 , and 𝑉 3 .
Problem 2 Parallel connection: Calculate the following: Currents 𝐼 1 , 𝐼 2 , 𝐼 3 and 𝐼 𝑒𝑞 . And Voltages 𝑉 1 , 𝑉 2 , and 𝑉 3 . +
𝑅 1 =8Ω
𝑅 2 =10Ω
𝑅 3 =6Ω
𝑉 𝑒𝑞 =12𝑉 +
𝑉 𝑒𝑞=12𝑉
𝑅 1 =8Ω
𝑅 2 =10Ω
𝑅 3 =6Ω

6. Electric Circuits
Complex circuit
𝐼 𝑒𝑞 = 18𝑉 6Ω =3𝐴

7. Electric Circuits
Problem 3 Composite connection: Calculate the following: Currents 𝐼 1 and 𝐼 2 .
𝑅 4 =11Ω
𝑅 5 =5Ω
𝑅 6 =3Ω
𝑉 𝑒𝑞 =24𝑉 +
𝑅 1 =8Ω
𝑅 3 =10Ω
𝑅 2 =9Ω
𝐼 2
𝐼 1

8. Electric Circuits 𝑅 2 =9Ω 𝑅 4 =11Ω
𝑅 5 =5Ω
𝑅 6 =3Ω
𝑉 𝑒𝑞 =24𝑉 +
𝑅 1 =8Ω
𝑅 3 =10Ω
𝑅 2 =9Ω
𝐼 2
𝐼 1
Problem 3 Composite connection: Calculate the following: Currents 𝐼 1 and 𝐼 2 .
𝑉 1 = 𝑉 𝑒𝑞 =24𝑉: parallel
𝑅 𝑎 =19Ω
𝑉 𝑒𝑞 =24𝑉 +
𝑅 1 =8Ω
𝑅 3 =10Ω
𝑅 2 =9Ω
𝐼 2
𝐼 1
𝐼 1 = 𝑉 1 𝑅 1 = 24𝑉 8Ω =3A
Parallel: 𝐼 2 = 𝐼 𝑒𝑞 − 𝐼 1 =4.55𝐴−3=1.55𝐴
𝑉 𝑒𝑞 =24𝑉 +
𝑅 1 =8Ω
𝑅 𝑏 =6.55Ω
𝑅 2 =9Ω
𝐼 2
𝐼 1
𝑉 𝑒𝑞 =24𝑉 +
𝑅 𝑒𝑞 =5.28Ω
𝑉 𝑒𝑞 =24𝑉 +
𝑅 1 =8Ω
𝑅 𝑐 =15.55Ω
𝐼 2
𝐼 1
𝐼 𝑒𝑞 = 𝑉 𝑒𝑞 𝑅 𝑒𝑞 = 24𝑉 5.28Ω =4.55A

9. Answer: 1,010 sec

10. Assignment

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17. Assignment 2
Figure

18. Assignment 3
Figure

19. ANSWERS TO ODD NUMBERS

20. eNd