Lecture Week 3

bull Please turn in your homework at the front of the room now

bull Weekly Schedule

bull Quiz 1 ndash Unit Conversions

bull Ohmrsquos Law (V=IR)bull Power

bull Series Equivalent Resistance

bull Workshopbull Homework

EE13051105 - Weekly Schedule

Next week ndash Lab Session Analog Discovery 101 Tutorial

MONDAY TUESDAY WED THURSDAY FRIDAY

730 am ndash1020 am

LABE301

1030 am ndash120 pm

LABE301

LABE301

LABE301

300 pm ndash420 pm

LectureAnnatoma Arif

BUSN 312

LectureAnnatoma Arif

BUSN 312

IEEE Mentorship Program

The IEEE UTEP student organization has a new mentorship program This is a program where freshman and sophomore engineering students get matched with juniors and seniors with industryresearch experience to help them out with their resumes how to get internships how to get involved on campus and technical skills

httpsformsgleRcTsNrQWcsEZ2gYS6

EE13051105 - Weekly Schedule

Next week ndash Lab Session Analog Discovery 101 Tutorial

MONDAY TUESDAY WED THURSDAY FRIDAY

730 am ndash1020 am

LABE301

1030 am ndash120 pm

LABE301

LABE301

LABE301

300 pm ndash420 pm

LectureAnnatoma Arif

BUSN 312

LectureAnnatoma Arif

BUSN 312

IEEE Mentorship Program

The IEEE UTEP student organization has a new mentorship program This is a program where freshman and sophomore engineering students get matched with juniors and seniors with industryresearch experience to help them out with their resumes how to get internships how to get involved on campus and technical skills

httpsformsgleRcTsNrQWcsEZ2gYS6

IEEE Mentorship Program

The IEEE UTEP student organization has a new mentorship program This is a program where freshman and sophomore engineering students get matched with juniors and seniors with industryresearch experience to help them out with their resumes how to get internships how to get involved on campus and technical skills

httpsformsgleRcTsNrQWcsEZ2gYS6

SPRING CAREER FAIR 2020

This fair is the only large-scale job fair held during the spring semester

Employers seeking students in business liberal arts and engineering and

science disciplines are invited to attend

Engineering amp Science Career EXPO (Day2)

Friday February 7 2020

900 am ndash 200 pm

Union Building East 3rd Floor

bull Please clear desks and turn off phones and put them in backpacks

bull You need penpencil straight edge and calculator

bull 20 minutes

bull Keep eyes on your own paper

bull Follow same format as for homework

bull Turn in your completed quiz at the front of the room

bull When you finish please sit quietly until everyone is finished

Quiz 1

Circuit Components

Source F Ulaby M Maharbiz Circuits 2nd Ed National Technology and Science Press 2013

or

LEARN TO

RECOGNIZE

CIRCUIT

SYMBOLS

Voltage and Current Measurements

Source F Ulaby M Maharbiz Circuits 2nd Ed National Technology and Science Press 2013

Ammeter (low resistance) measures current without dropping voltage

Voltmeter (high resistance) measures voltage without drawing current

HOW TO

MEASURE

VOLTAGE

HOW TO

MEASURE

CURRENT

NEVER PLACE

AMMETER IN PARALLEL

WITH CIRCUIT

COMPONENT

Ohmrsquos Law

119881 = 119868119877 (recall unit conversion 1V = 1A )

V ndash Voltage is measured in units of volts (V)

I ndash Current is measured in units of amps (A) where an amp is equal to one coulombsecond (Cs)

R ndash Resistance is measured in units of ohms ()

THERE ARE MANY WAYS

TO APPLY OHMrsquoS LAW

AND

WE WILL BEGIN EXPLORING

THEM IN THIS COURSE

I

What is current

Source F Ulaby M Maharbiz Circuits 2nd Ed National Technology and Science Press 2013

Charge Movement

DC vs AC

Charge Notation (Direction)

CURRENT

THE MOVEMENT

OF CHARGE

(ELECTRONS)

THROUGH A

CONDUCTOR

IF THERE IS

CURRENT THERE

IS AN ELECTRIC

FIELD

Ohmrsquos Law Visualized

OHMrsquoS LAW IS LIKE WATER

FLOWING IN A PIPEhellip

THE VOLTAGE IS LIKE THE PUMP

FORCING THE WATER THROUGH THE

PIPEhellip

THE RESISTANCE IS LIKE HAVING A

THINNER PIPE AND RESTRICTING

THE AMOUNT OF WATER GOING

THROUGH

Ohmrsquos Law ndash Voltage Current and Resistance

Ohmrsquos Law and Resistance

How are resistors used to change current

What are some ways that we can increase the current

- Use a smaller resistor

- Use resistors in parallel

LETrsquoS VISUALIZE OHMrsquoS LAWhellip

- Use a higher voltage

bull Please clear desks and turn off phones and put them in backpacks

bull You need penpencil straight edge and calculator

bull 20 minutes

bull Keep eyes on your own paper

bull Follow same format as for homework

bull Turn in your completed quiz at the front of the room

bull When you finish please sit quietly until everyone is finished

Quiz 1

Circuit Components

Source F Ulaby M Maharbiz Circuits 2nd Ed National Technology and Science Press 2013

or

LEARN TO

RECOGNIZE

CIRCUIT

SYMBOLS

Voltage and Current Measurements

Source F Ulaby M Maharbiz Circuits 2nd Ed National Technology and Science Press 2013

Ammeter (low resistance) measures current without dropping voltage

Voltmeter (high resistance) measures voltage without drawing current

HOW TO

MEASURE

VOLTAGE

HOW TO

MEASURE

CURRENT

NEVER PLACE

AMMETER IN PARALLEL

WITH CIRCUIT

COMPONENT

Ohmrsquos Law

119881 = 119868119877 (recall unit conversion 1V = 1A )

V ndash Voltage is measured in units of volts (V)

I ndash Current is measured in units of amps (A) where an amp is equal to one coulombsecond (Cs)

R ndash Resistance is measured in units of ohms ()

THERE ARE MANY WAYS

TO APPLY OHMrsquoS LAW

AND

WE WILL BEGIN EXPLORING

THEM IN THIS COURSE

I

What is current

Source F Ulaby M Maharbiz Circuits 2nd Ed National Technology and Science Press 2013

Charge Movement

DC vs AC

Charge Notation (Direction)

CURRENT

THE MOVEMENT

OF CHARGE

(ELECTRONS)

THROUGH A

CONDUCTOR

IF THERE IS

CURRENT THERE

IS AN ELECTRIC

FIELD

Ohmrsquos Law Visualized

OHMrsquoS LAW IS LIKE WATER

FLOWING IN A PIPEhellip

THE VOLTAGE IS LIKE THE PUMP

FORCING THE WATER THROUGH THE

PIPEhellip

THE RESISTANCE IS LIKE HAVING A

THINNER PIPE AND RESTRICTING

THE AMOUNT OF WATER GOING

THROUGH

Ohmrsquos Law ndash Voltage Current and Resistance

Ohmrsquos Law and Resistance

How are resistors used to change current

What are some ways that we can increase the current

- Use a smaller resistor

- Use resistors in parallel

LETrsquoS VISUALIZE OHMrsquoS LAWhellip

- Use a higher voltage

Circuit Components

Source F Ulaby M Maharbiz Circuits 2nd Ed National Technology and Science Press 2013

or

LEARN TO

RECOGNIZE

CIRCUIT

SYMBOLS

Voltage and Current Measurements

Source F Ulaby M Maharbiz Circuits 2nd Ed National Technology and Science Press 2013

Ammeter (low resistance) measures current without dropping voltage

Voltmeter (high resistance) measures voltage without drawing current

HOW TO

MEASURE

VOLTAGE

HOW TO

MEASURE

CURRENT

NEVER PLACE

AMMETER IN PARALLEL

WITH CIRCUIT

COMPONENT

Ohmrsquos Law

119881 = 119868119877 (recall unit conversion 1V = 1A )

V ndash Voltage is measured in units of volts (V)

I ndash Current is measured in units of amps (A) where an amp is equal to one coulombsecond (Cs)

R ndash Resistance is measured in units of ohms ()

THERE ARE MANY WAYS

TO APPLY OHMrsquoS LAW

AND

WE WILL BEGIN EXPLORING

THEM IN THIS COURSE

I

What is current

Source F Ulaby M Maharbiz Circuits 2nd Ed National Technology and Science Press 2013

Charge Movement

DC vs AC

Charge Notation (Direction)

CURRENT

THE MOVEMENT

OF CHARGE

(ELECTRONS)

THROUGH A

CONDUCTOR

IF THERE IS

CURRENT THERE

IS AN ELECTRIC

FIELD

Ohmrsquos Law Visualized

OHMrsquoS LAW IS LIKE WATER

FLOWING IN A PIPEhellip

THE VOLTAGE IS LIKE THE PUMP

FORCING THE WATER THROUGH THE

PIPEhellip

THE RESISTANCE IS LIKE HAVING A

THINNER PIPE AND RESTRICTING

THE AMOUNT OF WATER GOING

THROUGH

Ohmrsquos Law ndash Voltage Current and Resistance

Ohmrsquos Law and Resistance

How are resistors used to change current

What are some ways that we can increase the current

- Use a smaller resistor

- Use resistors in parallel

LETrsquoS VISUALIZE OHMrsquoS LAWhellip

- Use a higher voltage

Voltage and Current Measurements

Source F Ulaby M Maharbiz Circuits 2nd Ed National Technology and Science Press 2013

Ammeter (low resistance) measures current without dropping voltage

Voltmeter (high resistance) measures voltage without drawing current

HOW TO

MEASURE

VOLTAGE

HOW TO

MEASURE

CURRENT

NEVER PLACE

AMMETER IN PARALLEL

WITH CIRCUIT

COMPONENT

Ohmrsquos Law

119881 = 119868119877 (recall unit conversion 1V = 1A )

V ndash Voltage is measured in units of volts (V)

I ndash Current is measured in units of amps (A) where an amp is equal to one coulombsecond (Cs)

R ndash Resistance is measured in units of ohms ()

THERE ARE MANY WAYS

TO APPLY OHMrsquoS LAW

AND

WE WILL BEGIN EXPLORING

THEM IN THIS COURSE

I

What is current

Source F Ulaby M Maharbiz Circuits 2nd Ed National Technology and Science Press 2013

Charge Movement

DC vs AC

Charge Notation (Direction)

CURRENT

THE MOVEMENT

OF CHARGE

(ELECTRONS)

THROUGH A

CONDUCTOR

IF THERE IS

CURRENT THERE

IS AN ELECTRIC

FIELD

Ohmrsquos Law Visualized

OHMrsquoS LAW IS LIKE WATER

FLOWING IN A PIPEhellip

THE VOLTAGE IS LIKE THE PUMP

FORCING THE WATER THROUGH THE

PIPEhellip

THE RESISTANCE IS LIKE HAVING A

THINNER PIPE AND RESTRICTING

THE AMOUNT OF WATER GOING

THROUGH

Ohmrsquos Law ndash Voltage Current and Resistance

Ohmrsquos Law and Resistance

How are resistors used to change current

What are some ways that we can increase the current

- Use a smaller resistor

- Use resistors in parallel

LETrsquoS VISUALIZE OHMrsquoS LAWhellip

- Use a higher voltage

Ohmrsquos Law

119881 = 119868119877 (recall unit conversion 1V = 1A )

V ndash Voltage is measured in units of volts (V)

I ndash Current is measured in units of amps (A) where an amp is equal to one coulombsecond (Cs)

R ndash Resistance is measured in units of ohms ()

THERE ARE MANY WAYS

TO APPLY OHMrsquoS LAW

AND

WE WILL BEGIN EXPLORING

THEM IN THIS COURSE

I

What is current

Source F Ulaby M Maharbiz Circuits 2nd Ed National Technology and Science Press 2013

Charge Movement

DC vs AC

Charge Notation (Direction)

CURRENT

THE MOVEMENT

OF CHARGE

(ELECTRONS)

THROUGH A

CONDUCTOR

IF THERE IS

CURRENT THERE

IS AN ELECTRIC

FIELD

Ohmrsquos Law Visualized

OHMrsquoS LAW IS LIKE WATER

FLOWING IN A PIPEhellip

THE VOLTAGE IS LIKE THE PUMP

FORCING THE WATER THROUGH THE

PIPEhellip

THE RESISTANCE IS LIKE HAVING A

THINNER PIPE AND RESTRICTING

THE AMOUNT OF WATER GOING

THROUGH

Ohmrsquos Law ndash Voltage Current and Resistance

Ohmrsquos Law and Resistance

How are resistors used to change current

What are some ways that we can increase the current

- Use a smaller resistor

- Use resistors in parallel

LETrsquoS VISUALIZE OHMrsquoS LAWhellip

- Use a higher voltage

What is current

Source F Ulaby M Maharbiz Circuits 2nd Ed National Technology and Science Press 2013

Charge Movement

DC vs AC

Charge Notation (Direction)

CURRENT

THE MOVEMENT

OF CHARGE

(ELECTRONS)

THROUGH A

CONDUCTOR

IF THERE IS

CURRENT THERE

IS AN ELECTRIC

FIELD

Ohmrsquos Law Visualized

OHMrsquoS LAW IS LIKE WATER

FLOWING IN A PIPEhellip

THE VOLTAGE IS LIKE THE PUMP

FORCING THE WATER THROUGH THE

PIPEhellip

THE RESISTANCE IS LIKE HAVING A

THINNER PIPE AND RESTRICTING

THE AMOUNT OF WATER GOING

THROUGH

Ohmrsquos Law ndash Voltage Current and Resistance

Ohmrsquos Law and Resistance

How are resistors used to change current

What are some ways that we can increase the current

- Use a smaller resistor

- Use resistors in parallel

LETrsquoS VISUALIZE OHMrsquoS LAWhellip

- Use a higher voltage

Ohmrsquos Law Visualized

OHMrsquoS LAW IS LIKE WATER

FLOWING IN A PIPEhellip

THE VOLTAGE IS LIKE THE PUMP

FORCING THE WATER THROUGH THE

PIPEhellip

THE RESISTANCE IS LIKE HAVING A

THINNER PIPE AND RESTRICTING

THE AMOUNT OF WATER GOING

THROUGH

Ohmrsquos Law ndash Voltage Current and Resistance

Ohmrsquos Law and Resistance

How are resistors used to change current

What are some ways that we can increase the current

- Use a smaller resistor

- Use resistors in parallel

LETrsquoS VISUALIZE OHMrsquoS LAWhellip

- Use a higher voltage

Ohmrsquos Law ndash Voltage Current and Resistance

Ohmrsquos Law and Resistance

How are resistors used to change current

What are some ways that we can increase the current

- Use a smaller resistor

- Use resistors in parallel

LETrsquoS VISUALIZE OHMrsquoS LAWhellip

- Use a higher voltage

How Ohmrsquos Law is Applied

What information do you need to determine the current flowing through a resistor

119868 =1198811 minus 1198812

119877

V1

V2

R

I

CURRENT

A POTENTIAL DIFFERENCE

ACROSS A RESISTOR IS

REQUIREDIN ORDER FOR CURRENT

TO FLOW THROUGH IT

THE POTENTIAL

DIFFERENCE CREATES AN

ELECTRIC FIELD AND THE

ELECTRIC FIELD MOVES

THE CHARGE THAT

CREATES THE CURRENT

Electronics Wheel

VOLTAGE

RESISTANCE

CURRENT

POWER - LATER

Image Source httpwwwsengpielaudiocomFormulaWheelElectronicsgif

Electronics Wheel

VOLTAGE

RESISTANCE

CURRENT

POWER - LATER

Image Source httpwwwsengpielaudiocomFormulaWheelElectronicsgif

Variables Symbols and Units

VARIABLE SYMBOL UNIT SYMBOL UNIT CONVERSIONS

VOLTAGE V VOLTS V V = A V = JC

CURRENT I AMPS A A = Cs

RESISTANCE R OHMS

POWER P WATTS W W = Js

VARIABLE SYMBOL UNIT SYMBOL UNIT CONVERSIONS

ENERGY E JOULES J J = Nm

FORCE F NEWTON N N=kgms2

CHARGE q COULOMB C

CAPACITANCE C FARAD F F = CV

VOLTAGE ndash CURRENT ndash RESISTANCE - POWER

OTHERS ENERGY-FORCE-CHARGE-CAPACITANCE

Ohmrsquos Law ExampleEE 1305 Name Group Lab Date

A simple circuit with a 5 V source and a 1 k resistor generates a current (I) through the circuit (a) Use Ohmrsquos Law to determine the value of I (b) Convert the current in part (a) from A to mA

EquationsUnit Conv FiguresCircuits

Calculations

Solution

119868 =119881

119877=

5 119881อ1 119896

ቮ1 119896

103อ119860

119881= 0005 119860

I = 0005 A or 5 mA

103 = 1 119896 103119898119860 = 1 119860

119881 = 119860

IR = 1k5V

119881 = 119868119877

119868 =0005 119860

อ103119898119860

119860= 5119898119860

Power can be supplieddelivered to a circuit or it can be absorbed by a circuit component

If power is supplied by a circuit component (battery) the power is negative - CURRENT FLOWING FROM ndash TO +

If power is absorbed by a circuit component the power is positive ndashCURRENT FLOWING FROM + TO ndash

POWER CONSUMMED

+

POWER GENERATED

-

+

-

+

-

Power and Passive Sign Convention

While voltage is related to Potential Energy and is equal to

119881 = 119868119877

ldquoThe Power is equal to the voltage across a device times the current entering through its positive terminalrdquo

or

ldquoWhen one joule of energy is required to transfer one coulomb of charge through a device in one second this produces a rate of energy transfer of one Wattrdquo

119875 = 119868119881

The algebraic sum of all power in a circuit must equal zero based on the LAW OF CONSERVATION OF POWER

Sources Engineering Circuit Analysis by Hayt Kemmerly and Durbin2007 and Circuits by Ulaby and Maharbiz 2010

Power and Passive Sign Convention

V

EQUIVALENT

CIRCUIT

VReq

119868

Series Circuit - Equivalent Circuit

119929119942119954 = 119929120783 + 119929120784 + 119929120785 + hellip119929119951

CURRENT THROUGH ALL RESISTORS IS THE SAME AND

EQUAL TO THE CIRCUIT CURRENT OF THE EQUIVALENT

CIRCUIT

119920 =119933

119929119942119954

(1) Calculate the Equivalent Resistance (Req)

(2) Use Ohmrsquos Law to determine the circuit current

(3) Then use Ohmrsquos Law to determine the voltage drop across each resistor

119933 = 119920119929120783

P1 A current of 6 mA flows through the circuit below If a 12 V voltage

supply is used what value of R (in k) is required to generate the 6 mA

current Show all units and unit conversions

EquationsUnit Conv FiguresCircuits

103 = 1 119896 103119898119860 = 1 119860

119881 = 119860

I= 6 mA

R = 12V

119881 = 119868119877

P2 - The current flowing through three resistors in series (R1 R2 and R3) is

769 mA Since the three resistors are in series the current flowing through

each resistor is the same

(a) Use Ohmrsquos Law to determine the voltage drop across each

resistor

(b) Find the power consumed by each resistor (R1 R2 and R3)

(c) Add the voltage drop across each resistor Show all units and

unit conversions for each of your calculations

Home Work 2- Problem 2 ndash You step out of the room and your lab mate

changes the resistors on your circuit Since the three resistors are in series

the current flowing through each resistor is the same

(a) Compute the equivalent resistance Req of the circuit (redraw it)

(b) Use Ohmrsquos Law to compute the new current value

(b) Determine the new voltage drop across each resistor

(b) Find the power consumed by each resistor (R1 R2 and R3)

(c) Add the voltage drop across each resistor Show all units and

unit conversions for each of your calculations

Group Problem

Ω

Ω

I

Using Ohmrsquos Law [a] find the equivalent resistance (Req) [b] the total

current (I) and [c] the voltage drop for R1 and R2 for the circuit below

[d] Calculate the power absorbed by R1 and R2 SHOW ALL UNITS

AND UNIT CONVERSIONS USING THE PROBLEM SOLVING

FORMAT PRACTICED IN CLASS FOR UNIT CONVERSIONS

REDRAW THE CIRCUIT WHEN YOU COMPUTE Req

Whatrsquos Next in Week 4 (218)

Will introducehellip

LAB

bull Using Analog Discovery

LECTURE

bull Quiz 2 ndash Fundamentals of Electricity

bull Circuit Elements and Equivalent Resistances

Please bring laptops to all labs

QuestionsSee you in the next class

Ohmrsquos Law ExampleEE 1305 Name Group Lab Date

A simple circuit with a 5 V source and a 1 k resistor generates a current (I) through the circuit (a) Use Ohmrsquos Law to determine the value of I (b) Convert the current in part (a) from A to mA

EquationsUnit Conv FiguresCircuits

Calculations

Solution

119868 =119881

119877=

5 119881อ1 119896

ቮ1 119896

103อ119860

119881= 0005 119860

I = 0005 A or 5 mA

103 = 1 119896 103119898119860 = 1 119860

119881 = 119860

IR = 1k5V

119881 = 119868119877

119868 =0005 119860

อ103119898119860

119860= 5119898119860

Power can be supplieddelivered to a circuit or it can be absorbed by a circuit component

If power is supplied by a circuit component (battery) the power is negative - CURRENT FLOWING FROM ndash TO +

If power is absorbed by a circuit component the power is positive ndashCURRENT FLOWING FROM + TO ndash

POWER CONSUMMED

+

POWER GENERATED

-

+

-

+

-

Power and Passive Sign Convention

While voltage is related to Potential Energy and is equal to

119881 = 119868119877

ldquoThe Power is equal to the voltage across a device times the current entering through its positive terminalrdquo

or

ldquoWhen one joule of energy is required to transfer one coulomb of charge through a device in one second this produces a rate of energy transfer of one Wattrdquo

119875 = 119868119881

The algebraic sum of all power in a circuit must equal zero based on the LAW OF CONSERVATION OF POWER

Sources Engineering Circuit Analysis by Hayt Kemmerly and Durbin2007 and Circuits by Ulaby and Maharbiz 2010

Power and Passive Sign Convention

V

EQUIVALENT

CIRCUIT

VReq

119868

Series Circuit - Equivalent Circuit

119929119942119954 = 119929120783 + 119929120784 + 119929120785 + hellip119929119951

CURRENT THROUGH ALL RESISTORS IS THE SAME AND

EQUAL TO THE CIRCUIT CURRENT OF THE EQUIVALENT

CIRCUIT

119920 =119933

119929119942119954

(1) Calculate the Equivalent Resistance (Req)

(2) Use Ohmrsquos Law to determine the circuit current

(3) Then use Ohmrsquos Law to determine the voltage drop across each resistor

119933 = 119920119929120783

P1 A current of 6 mA flows through the circuit below If a 12 V voltage

supply is used what value of R (in k) is required to generate the 6 mA

current Show all units and unit conversions

EquationsUnit Conv FiguresCircuits

103 = 1 119896 103119898119860 = 1 119860

119881 = 119860

I= 6 mA

R = 12V

119881 = 119868119877

P2 - The current flowing through three resistors in series (R1 R2 and R3) is

769 mA Since the three resistors are in series the current flowing through

each resistor is the same

(a) Use Ohmrsquos Law to determine the voltage drop across each

resistor

(b) Find the power consumed by each resistor (R1 R2 and R3)

(c) Add the voltage drop across each resistor Show all units and

unit conversions for each of your calculations

Home Work 2- Problem 2 ndash You step out of the room and your lab mate

changes the resistors on your circuit Since the three resistors are in series

the current flowing through each resistor is the same

(a) Compute the equivalent resistance Req of the circuit (redraw it)

(b) Use Ohmrsquos Law to compute the new current value

(b) Determine the new voltage drop across each resistor

(b) Find the power consumed by each resistor (R1 R2 and R3)

(c) Add the voltage drop across each resistor Show all units and

unit conversions for each of your calculations

Group Problem

Ω

Ω

I

Using Ohmrsquos Law [a] find the equivalent resistance (Req) [b] the total

current (I) and [c] the voltage drop for R1 and R2 for the circuit below

[d] Calculate the power absorbed by R1 and R2 SHOW ALL UNITS

AND UNIT CONVERSIONS USING THE PROBLEM SOLVING

FORMAT PRACTICED IN CLASS FOR UNIT CONVERSIONS

REDRAW THE CIRCUIT WHEN YOU COMPUTE Req

Whatrsquos Next in Week 4 (218)

Will introducehellip

LAB

bull Using Analog Discovery

LECTURE

bull Quiz 2 ndash Fundamentals of Electricity

bull Circuit Elements and Equivalent Resistances

Please bring laptops to all labs

QuestionsSee you in the next class

Power can be supplieddelivered to a circuit or it can be absorbed by a circuit component

If power is supplied by a circuit component (battery) the power is negative - CURRENT FLOWING FROM ndash TO +

If power is absorbed by a circuit component the power is positive ndashCURRENT FLOWING FROM + TO ndash

POWER CONSUMMED

+

POWER GENERATED

-

+

-

+

-

Power and Passive Sign Convention

While voltage is related to Potential Energy and is equal to

119881 = 119868119877

ldquoThe Power is equal to the voltage across a device times the current entering through its positive terminalrdquo

or

ldquoWhen one joule of energy is required to transfer one coulomb of charge through a device in one second this produces a rate of energy transfer of one Wattrdquo

119875 = 119868119881

The algebraic sum of all power in a circuit must equal zero based on the LAW OF CONSERVATION OF POWER

Sources Engineering Circuit Analysis by Hayt Kemmerly and Durbin2007 and Circuits by Ulaby and Maharbiz 2010

Power and Passive Sign Convention

V

EQUIVALENT

CIRCUIT

VReq

119868

Series Circuit - Equivalent Circuit

119929119942119954 = 119929120783 + 119929120784 + 119929120785 + hellip119929119951

CURRENT THROUGH ALL RESISTORS IS THE SAME AND

EQUAL TO THE CIRCUIT CURRENT OF THE EQUIVALENT

CIRCUIT

119920 =119933

119929119942119954

(1) Calculate the Equivalent Resistance (Req)

(2) Use Ohmrsquos Law to determine the circuit current

(3) Then use Ohmrsquos Law to determine the voltage drop across each resistor

119933 = 119920119929120783

P1 A current of 6 mA flows through the circuit below If a 12 V voltage

supply is used what value of R (in k) is required to generate the 6 mA

current Show all units and unit conversions

EquationsUnit Conv FiguresCircuits

103 = 1 119896 103119898119860 = 1 119860

119881 = 119860

I= 6 mA

R = 12V

119881 = 119868119877

P2 - The current flowing through three resistors in series (R1 R2 and R3) is

769 mA Since the three resistors are in series the current flowing through

each resistor is the same

(a) Use Ohmrsquos Law to determine the voltage drop across each

resistor

(b) Find the power consumed by each resistor (R1 R2 and R3)

(c) Add the voltage drop across each resistor Show all units and

unit conversions for each of your calculations

Home Work 2- Problem 2 ndash You step out of the room and your lab mate

changes the resistors on your circuit Since the three resistors are in series

the current flowing through each resistor is the same

(a) Compute the equivalent resistance Req of the circuit (redraw it)

(b) Use Ohmrsquos Law to compute the new current value

(b) Determine the new voltage drop across each resistor

(b) Find the power consumed by each resistor (R1 R2 and R3)

(c) Add the voltage drop across each resistor Show all units and

unit conversions for each of your calculations

Group Problem

Ω

Ω

I

Using Ohmrsquos Law [a] find the equivalent resistance (Req) [b] the total

current (I) and [c] the voltage drop for R1 and R2 for the circuit below

[d] Calculate the power absorbed by R1 and R2 SHOW ALL UNITS

AND UNIT CONVERSIONS USING THE PROBLEM SOLVING

FORMAT PRACTICED IN CLASS FOR UNIT CONVERSIONS

REDRAW THE CIRCUIT WHEN YOU COMPUTE Req

Whatrsquos Next in Week 4 (218)

Will introducehellip

LAB

bull Using Analog Discovery

LECTURE

bull Quiz 2 ndash Fundamentals of Electricity

bull Circuit Elements and Equivalent Resistances

Please bring laptops to all labs

QuestionsSee you in the next class

While voltage is related to Potential Energy and is equal to

119881 = 119868119877

ldquoThe Power is equal to the voltage across a device times the current entering through its positive terminalrdquo

or

ldquoWhen one joule of energy is required to transfer one coulomb of charge through a device in one second this produces a rate of energy transfer of one Wattrdquo

119875 = 119868119881

The algebraic sum of all power in a circuit must equal zero based on the LAW OF CONSERVATION OF POWER

Sources Engineering Circuit Analysis by Hayt Kemmerly and Durbin2007 and Circuits by Ulaby and Maharbiz 2010

Power and Passive Sign Convention

V

EQUIVALENT

CIRCUIT

VReq

119868

Series Circuit - Equivalent Circuit

119929119942119954 = 119929120783 + 119929120784 + 119929120785 + hellip119929119951

CURRENT THROUGH ALL RESISTORS IS THE SAME AND

EQUAL TO THE CIRCUIT CURRENT OF THE EQUIVALENT

CIRCUIT

119920 =119933

119929119942119954

(1) Calculate the Equivalent Resistance (Req)

(2) Use Ohmrsquos Law to determine the circuit current

(3) Then use Ohmrsquos Law to determine the voltage drop across each resistor

119933 = 119920119929120783

P1 A current of 6 mA flows through the circuit below If a 12 V voltage

supply is used what value of R (in k) is required to generate the 6 mA

current Show all units and unit conversions

EquationsUnit Conv FiguresCircuits

103 = 1 119896 103119898119860 = 1 119860

119881 = 119860

I= 6 mA

R = 12V

119881 = 119868119877

P2 - The current flowing through three resistors in series (R1 R2 and R3) is

769 mA Since the three resistors are in series the current flowing through

each resistor is the same

(a) Use Ohmrsquos Law to determine the voltage drop across each

resistor

(b) Find the power consumed by each resistor (R1 R2 and R3)

(c) Add the voltage drop across each resistor Show all units and

unit conversions for each of your calculations

Home Work 2- Problem 2 ndash You step out of the room and your lab mate

changes the resistors on your circuit Since the three resistors are in series

the current flowing through each resistor is the same

(a) Compute the equivalent resistance Req of the circuit (redraw it)

(b) Use Ohmrsquos Law to compute the new current value

(b) Determine the new voltage drop across each resistor

(b) Find the power consumed by each resistor (R1 R2 and R3)

(c) Add the voltage drop across each resistor Show all units and

unit conversions for each of your calculations

Group Problem

Ω

Ω

I

Using Ohmrsquos Law [a] find the equivalent resistance (Req) [b] the total

current (I) and [c] the voltage drop for R1 and R2 for the circuit below

[d] Calculate the power absorbed by R1 and R2 SHOW ALL UNITS

AND UNIT CONVERSIONS USING THE PROBLEM SOLVING

FORMAT PRACTICED IN CLASS FOR UNIT CONVERSIONS

REDRAW THE CIRCUIT WHEN YOU COMPUTE Req

Whatrsquos Next in Week 4 (218)

Will introducehellip

LAB

bull Using Analog Discovery

LECTURE

bull Quiz 2 ndash Fundamentals of Electricity

bull Circuit Elements and Equivalent Resistances

Please bring laptops to all labs

QuestionsSee you in the next class

V

EQUIVALENT

CIRCUIT

VReq

119868

Series Circuit - Equivalent Circuit

119929119942119954 = 119929120783 + 119929120784 + 119929120785 + hellip119929119951

CURRENT THROUGH ALL RESISTORS IS THE SAME AND

EQUAL TO THE CIRCUIT CURRENT OF THE EQUIVALENT

CIRCUIT

119920 =119933

119929119942119954

(1) Calculate the Equivalent Resistance (Req)

(2) Use Ohmrsquos Law to determine the circuit current

(3) Then use Ohmrsquos Law to determine the voltage drop across each resistor

119933 = 119920119929120783

P1 A current of 6 mA flows through the circuit below If a 12 V voltage

supply is used what value of R (in k) is required to generate the 6 mA

current Show all units and unit conversions

EquationsUnit Conv FiguresCircuits

103 = 1 119896 103119898119860 = 1 119860

119881 = 119860

I= 6 mA

R = 12V

119881 = 119868119877

P2 - The current flowing through three resistors in series (R1 R2 and R3) is

769 mA Since the three resistors are in series the current flowing through

each resistor is the same

(a) Use Ohmrsquos Law to determine the voltage drop across each

resistor

(b) Find the power consumed by each resistor (R1 R2 and R3)

(c) Add the voltage drop across each resistor Show all units and

unit conversions for each of your calculations

Home Work 2- Problem 2 ndash You step out of the room and your lab mate

changes the resistors on your circuit Since the three resistors are in series

the current flowing through each resistor is the same

(a) Compute the equivalent resistance Req of the circuit (redraw it)

(b) Use Ohmrsquos Law to compute the new current value

(b) Determine the new voltage drop across each resistor

(b) Find the power consumed by each resistor (R1 R2 and R3)

(c) Add the voltage drop across each resistor Show all units and

unit conversions for each of your calculations

Group Problem

Ω

Ω

I

Using Ohmrsquos Law [a] find the equivalent resistance (Req) [b] the total

current (I) and [c] the voltage drop for R1 and R2 for the circuit below

[d] Calculate the power absorbed by R1 and R2 SHOW ALL UNITS

AND UNIT CONVERSIONS USING THE PROBLEM SOLVING

FORMAT PRACTICED IN CLASS FOR UNIT CONVERSIONS

REDRAW THE CIRCUIT WHEN YOU COMPUTE Req

Whatrsquos Next in Week 4 (218)

Will introducehellip

LAB

bull Using Analog Discovery

LECTURE

bull Quiz 2 ndash Fundamentals of Electricity

bull Circuit Elements and Equivalent Resistances

Please bring laptops to all labs

QuestionsSee you in the next class

P1 A current of 6 mA flows through the circuit below If a 12 V voltage

supply is used what value of R (in k) is required to generate the 6 mA

current Show all units and unit conversions

EquationsUnit Conv FiguresCircuits

103 = 1 119896 103119898119860 = 1 119860

119881 = 119860

I= 6 mA

R = 12V

119881 = 119868119877

P2 - The current flowing through three resistors in series (R1 R2 and R3) is

769 mA Since the three resistors are in series the current flowing through

each resistor is the same

(a) Use Ohmrsquos Law to determine the voltage drop across each

resistor

(b) Find the power consumed by each resistor (R1 R2 and R3)

(c) Add the voltage drop across each resistor Show all units and

unit conversions for each of your calculations

Home Work 2- Problem 2 ndash You step out of the room and your lab mate

changes the resistors on your circuit Since the three resistors are in series

the current flowing through each resistor is the same

(a) Compute the equivalent resistance Req of the circuit (redraw it)

(b) Use Ohmrsquos Law to compute the new current value

(b) Determine the new voltage drop across each resistor

(b) Find the power consumed by each resistor (R1 R2 and R3)

(c) Add the voltage drop across each resistor Show all units and

unit conversions for each of your calculations

Group Problem

Ω

Ω

I

Using Ohmrsquos Law [a] find the equivalent resistance (Req) [b] the total

current (I) and [c] the voltage drop for R1 and R2 for the circuit below

[d] Calculate the power absorbed by R1 and R2 SHOW ALL UNITS

AND UNIT CONVERSIONS USING THE PROBLEM SOLVING

FORMAT PRACTICED IN CLASS FOR UNIT CONVERSIONS

REDRAW THE CIRCUIT WHEN YOU COMPUTE Req

Whatrsquos Next in Week 4 (218)

Will introducehellip

LAB

bull Using Analog Discovery

LECTURE

bull Quiz 2 ndash Fundamentals of Electricity

bull Circuit Elements and Equivalent Resistances

Please bring laptops to all labs

QuestionsSee you in the next class

P2 - The current flowing through three resistors in series (R1 R2 and R3) is

769 mA Since the three resistors are in series the current flowing through

each resistor is the same

(a) Use Ohmrsquos Law to determine the voltage drop across each

resistor

(b) Find the power consumed by each resistor (R1 R2 and R3)

(c) Add the voltage drop across each resistor Show all units and

unit conversions for each of your calculations

Home Work 2- Problem 2 ndash You step out of the room and your lab mate

changes the resistors on your circuit Since the three resistors are in series

the current flowing through each resistor is the same

(a) Compute the equivalent resistance Req of the circuit (redraw it)

(b) Use Ohmrsquos Law to compute the new current value

(b) Determine the new voltage drop across each resistor

(b) Find the power consumed by each resistor (R1 R2 and R3)

(c) Add the voltage drop across each resistor Show all units and

unit conversions for each of your calculations

Group Problem

Ω

Ω

I

Using Ohmrsquos Law [a] find the equivalent resistance (Req) [b] the total

current (I) and [c] the voltage drop for R1 and R2 for the circuit below

[d] Calculate the power absorbed by R1 and R2 SHOW ALL UNITS

AND UNIT CONVERSIONS USING THE PROBLEM SOLVING

FORMAT PRACTICED IN CLASS FOR UNIT CONVERSIONS

REDRAW THE CIRCUIT WHEN YOU COMPUTE Req

Whatrsquos Next in Week 4 (218)

Will introducehellip

LAB

bull Using Analog Discovery

LECTURE

bull Quiz 2 ndash Fundamentals of Electricity

bull Circuit Elements and Equivalent Resistances

Please bring laptops to all labs

QuestionsSee you in the next class

Home Work 2- Problem 2 ndash You step out of the room and your lab mate

changes the resistors on your circuit Since the three resistors are in series

the current flowing through each resistor is the same

(a) Compute the equivalent resistance Req of the circuit (redraw it)

(b) Use Ohmrsquos Law to compute the new current value

(b) Determine the new voltage drop across each resistor

(b) Find the power consumed by each resistor (R1 R2 and R3)

(c) Add the voltage drop across each resistor Show all units and

unit conversions for each of your calculations

Group Problem

Ω

Ω

I

Using Ohmrsquos Law [a] find the equivalent resistance (Req) [b] the total

current (I) and [c] the voltage drop for R1 and R2 for the circuit below

[d] Calculate the power absorbed by R1 and R2 SHOW ALL UNITS

AND UNIT CONVERSIONS USING THE PROBLEM SOLVING

FORMAT PRACTICED IN CLASS FOR UNIT CONVERSIONS

REDRAW THE CIRCUIT WHEN YOU COMPUTE Req

Whatrsquos Next in Week 4 (218)

Will introducehellip

LAB

bull Using Analog Discovery

LECTURE

bull Quiz 2 ndash Fundamentals of Electricity

bull Circuit Elements and Equivalent Resistances

Please bring laptops to all labs

QuestionsSee you in the next class

Group Problem

Ω

Ω

I

Using Ohmrsquos Law [a] find the equivalent resistance (Req) [b] the total

current (I) and [c] the voltage drop for R1 and R2 for the circuit below

[d] Calculate the power absorbed by R1 and R2 SHOW ALL UNITS

AND UNIT CONVERSIONS USING THE PROBLEM SOLVING

FORMAT PRACTICED IN CLASS FOR UNIT CONVERSIONS

REDRAW THE CIRCUIT WHEN YOU COMPUTE Req

Whatrsquos Next in Week 4 (218)

Will introducehellip

LAB

bull Using Analog Discovery

LECTURE

bull Quiz 2 ndash Fundamentals of Electricity

bull Circuit Elements and Equivalent Resistances

Please bring laptops to all labs

QuestionsSee you in the next class

Whatrsquos Next in Week 4 (218)

Will introducehellip

LAB

bull Using Analog Discovery

LECTURE

bull Quiz 2 ndash Fundamentals of Electricity

bull Circuit Elements and Equivalent Resistances

Please bring laptops to all labs

QuestionsSee you in the next class

QuestionsSee you in the next class