CST1511 Basic Electricity - 2
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CST1511 Basic Electricity - 2 Extra Credit Lecture Gary C. Meyer, Instructor
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CST1511 Basic Electricity - 2. Extra Credit Lecture Gary C. Meyer, Instructor. Review of Ohms Law/Power Formulas. E = IR I = E/R R = E/I P = EI P = I 2 R P = E 2 /R. Series Resistors . R(Total) = R1 +R2 + R3 Example:. R1 = 15 Ω R2 = 10 Ω R3 = 5 Ω. - PowerPoint PPT Presentation
Transcript of CST1511 Basic Electricity - 2
CST1511_Basic Electricity - 2
CST1511Basic Electricity - 2Extra Credit Lecture
Gary C. Meyer, Instructor1Review of Ohms Law/Power FormulasE = IRI = E/RR = E/I
P = EIP = I2RP = E2/R
2Series Resistors R(Total) = R1 +R2 + R3Example:
R1 = 15 R2 = 10 R3 = 5R (Total) = _______
3Series Resistors R(Total) = R1 +R2 + R3Example:
R1 = 15 R2 = 10 R3 = 5R (Total) = _ 30 ohms __
4Series Resistors R(Total) = R1 +R2 + R3Example:
R1 = 15 R2 = 10 R3 = 5I (Total) =+ 30 V -
5Series Resistors R(Total) = R1 +R2 + R3Example:
R1 = 15 R2 = 10 R3 = 5I (Total) = E/R = 30/30 = 1 A + 30 V -
6Series Resistors R(Total) = R1 +R2 + R3Example:
R1 = 15 R2 = 10 R3 = 5V (R2) = _____________ + 30 V -
7Series Resistors R(Total) = R1 +R2 + R3Example:
R1 = 15 R2 = 10 R3 = 5V (R2) = I x R = 1 x 10 = 10 v + 30 V -
8Current in Series CircuitUse Ohms LawExample:R1 = 8k ohmI(R1) =
R2 = 2k ohm
E = 10 voltsI (R1) = ?
9Current in Series CircuitUse Ohms LawExample:R1 = 8k ohmIR1 =10/(8000 + 2000) = 0.001 Amps
R2 = 2k ohm
E = 10 voltsI R1 = ?
10Voltage in Series CircuitVoltage Divides Across ResistorsExample: First Find Current. Next find voltages.R1 = 1k ohmI =
R2 = 2k ohm
E = 100 voltsV1 = I1 x R1V2 = I2 x R2V1 = V2 = 11Voltage in Series CircuitVoltage Divides Across ResistorsExample: First Find Current. Next find voltages.R1 = 1k ohmI =100/(1000 + 2000) = 0.0333 Amps
R2 = 2k ohm
E = 100 voltsV1 = I1 x R1V2 = I2 x R2V1 = 0.0333 x 1000 = 33.3 v V2 = 0.0333 x 2000 = 66.6 v 12Parallel Resistors (For Two)R(Total) = (R1 x R2)/(R1 + R2)Example: Rt = ?
R1 = 100R (Total) =R2 = 5013Parallel Resistors (For Two)R(Total) = (R1 x R2)/(R1 + R2)Example: Rt = ?
R1 = 100R (Total) =(100 x 50)/150 = 33.33R2 = 5014Parallel Resistors (For Two)R(Total) = (R1 x R2)/(R1 + R2)Example: Rt = ?
R1 = 2 kohmsR (Total) = ?R2 = 3 kohms15Parallel Resistors (For Two)R(Total) = (R1 x R2)/(R1 + R2)Example: Rt = ?
R1 = 2 kohmsR (Total) =(2000 x 3000)/5000 = 1200 R2 = 3 kohms16Current In Parallel CircuitUse Ohms LawExample: I1 = I2=
R1 = 25E = 100 vE/R1 = 100/25 = 4 AR2 = 50
E/R2 = 100/50 = 2 AI1 + I2 = 6 AmpsIt =17Power In Parallel CircuitUse Power FormulasExample: P1 = P2=
R1 = 25E = 100 vE x I = 100 x 4 = 400 wattsR2 = 50
E x I = 100 x 2 = 200 wattsP1 + P2 = 600 wattsPt =18Parallel Resistors1/R(Total) = 1/R1 + 1/R2 + 1/R3Example: 1/Rt = 1/3 + 1/5 + 1/10 = .33 + .20 + 0.10 = 0.63
R1 = 3R (Total) = 1/0.63 = 1.59 ohms R2 = 5R3 = 1019Parallel Resistors1/R(Total) = 1/R1 + 1/R2 + 1/R3Problem
R1 = 2 kR (Total) = ______________R2 = 500R3 = 1020Parallel Resistors1/R(Total) = 1/R1 + 1/R2 + 1/R3Problem
R1 = 2 kR (Total) = 9.75 ohmsR2 = 500R3 = 101/R (total) = 1/2000 + 1/500 +1/10
1/R (Total)= .0005 + .002 + .1
1/R (Total) = .1025
R (Total) = 1/0.1025 21Parallel Resistors1/R(Total) = 1/R1 + 1/R2 + 1/R3Problem I = E/R
R1 = 2 kR2 = 500R3 = 1012 vSolve for all currents.
I (R1) =
I (R2) =
I (R3) =
I (total) = 22Parallel Resistors1/R(Total) = 1/R1 + 1/R2 + 1/R3Problem I = E/R
R1 = 2 kR2 = 500R3 = 1012 vSolve for all currents.
I (R1) = 12/2000 = .006 A
I (R2) = 12/500 = .024 A
I (R3) = 12 /10 = 1.2 A
I (total) = 1.230 A23Series/Parallel ResistorsUse Same PrinciplesExample:
R1 = 100R (Total) =100 + (50x50)/(50+50) + 60 = 185R2 = 50
R3 = 50R4 = 6024Currents in Combined CircuitUse Resistance Rules + Ohms LawExample: Rt = 185 ohms from a previous example.
R1 = 100I (Total) =E/R = 370/185 = 2 AR2 = 50
R3 = 50R4 = 60
E = 370 vIR2 = ? IR3 =?IR2 = IR3 = 1 AEqual resistors = Equal currents25Voltages in Combined CircuitUse Resistance Rules + Ohms LawExample: Rt = 185 ohms from previous example.
R1 = 100I (Total) =E/R = 370/185 = 2 AR2 = 50
R3 = 50R4 = 60
E = 370 vVR1 =IR1 x R1 = 2 x 100 = 200 v26Voltages in Combined CircuitUse Resistance Rules + Ohms LawExample: Rt = 185 ohms from previous example.
R1 = 100I (Total) =E/R = 370/185 = 2 AR2 = 50
R3 = 50R4 = 60
E = 370 vVR2 =IR2 x R2 = 1 x 50 = 50 v27Voltages in Combined CircuitUse Resistance Rules + Ohms LawExample: Rt = 185 ohms from previous example.
R1 = 100I (Total) =E/R = 370/185 = 2 AR2 = 50
R3 = 50R4 = 60
E = 370 vVR4 =IR3 x R3 = 2 x 60 = 120 v28Parallel Resistor CurrentsExample ProblemExample: What is the current in the 20 ohm resistor?
R1 = 100R2 =20
R3 = 40R4 = 100It = 0.6 AIR2 = R3/(R2 + R3) x (It) = 40/60 x .6 = 0.4 AIR3 = R2/(R2 + R3) x (It) = 20/60 x .6 = 0.2 AIR2IR329Parallel Resistor CurrentsProblemExample: What is the current in the 20 ohm resistor?
R1 = 50R2 =10
R3 = 10R4 = 20It = 1.0 AIR2 = R3/(R2 + R3) x (It) =IR3 = R2/(R2 + R3) x (It) =IR2IR330Parallel/Series Resistor VoltagesProblemExample: What is the current in the 20 ohm resistor?
R1 = 50R2 =10
R3 = 10R4 = 20It = 1.0 AV (R1) =V (R2) =IR2IR3V (R4) =V (Total) =31Parallel/Series Resistor VoltagesSolutionExample: What is the current in the 20 ohm resistor?
R1 = 50R2 =10
R3 = 10R4 = 20It = 1.0 AV (R1) = 1 x 50 = 50vV (R2) = 0.5 x 10 = 5 vIR2IR3V (R4) = 1 x 20 = 20 vV (Total) = 50 + 5 + 20 = 75 v32Complete Worksheet 10Basic Electricity - 2Optional Extra Credit
JPG FilePlace Worksheet in Dropbox for Worksheet 1033
