CURRENT ELECTRICITY. Electric Currents

Save this PDF as:

Size: px
Start display at page:

Transcription

1 1 CURRENT ELECTRICITY Electric Currents Charges that produce repulsion and attraction between objects can also produce an electric current if the charge can flow though it. An electric current is actually the flow of electric charge moving a particular direction. To maintain an electric current, the charge needs a continuous path to travel around (closed circuit) Convectional Current and Electron Flow Electron Flow When electric currents pass through a circuit the electrons in the conductor go through the conductor to produce a flow of negative charge in the direction they travel. The negative charge flows from the negative points to positive points. This is the opposite to the direction of conventional current flow. Conventional Currents Early experiments believe that electricity is the flow of positive charge around the circuit. We therefore represent the flow of electric current as from a positively charged point to a negatively charged point. We use arrows to indicate the direction of the current flow and we call this direction conventional current direction conventional current electron flow Closed Circuit A closed circuit is one which there is an unbroken charge in which the charge can continuously flow. An Open Circuit An open circuit is one which has a break at one or more points of the path so that no current can flow in the circuit.

2 2 A Short Circuit A short circuit acts as a by pass for the electric current by providing an easier path for the current to flow. Series and Parallel Connections There are basically two ways in which conductors can be joined together in a circuit. These are: a) Series Connections The lamps in the diagram above are connected in series. When lit they shine at equal brightness. That means that the same current flows through all the lamps. If one lamp fails or is loose the circuit is broken, hence no current flows and all the lamps go off. b) Parallel Connections The lamps in the diagram above are in parallel connection. In parallel connection the current splits up and only part of the current flows through each lamp. If one of the lamp fails it does not affect the other lamps in the circuit.

3 3 Definitions Current (I) Units: Amperes (A) A current of one (1) ampere is the flow of charge at a rate of one (1) coulomb per second. Current is the force between the current carrying conductors. We can use the ammeter to measure the current. One of the formulas we can use to measure the current is: current = charge time Q I = Q t I t Charge (Q) Units: Coulombs (C) A Coulomb is the quantity of electric charge, which passes a point in the conductor at a steady current of one (1) ampere for one (1) second. charge = current time Q = I t Potential Difference (p.d.) Units: Volts (V) The potential difference between two points is the work done per coulomb when electrical energy is converted to another form of energy when current flows through a circuit. potential difference = energy charge W V = W Q V Q Electromotive Force (e.m.f.) Units: Volts (V) An electromotive force is the work done per coulomb when another form of energy is converted to electrical energy at a cell or generator. The e.m.f. is the total amount of energy a cell or a generator can produce and it is the sum of all the p.d. inserted. Both the electromotive force and the potential difference can be measured by using the voltmeter. N.B. one (1) volt = one (1) joule / coulomb [1 J/C]

4 4 Examples 1. A battery circulates a charge around a circuit of one (1) minute. If the current in the circuit is five (5) amperes, what quantity of charge passes through the battery? 2. A charge of 120 coulombs goes through a lamp every two minutes. Calculate the electric current. 3. A current of 20 amps flows through a heater for one (1) hour converts joules of electrical energy into heat energy. Calculate: (a) the total charge flowing through the heater. (b) p.d. across the heater. 4. A battery circulates 80 C of charge around a circuit. If the p.d. across a lamp in the circuit is 12 volts. How much energy is converted into heat and the light by the lamp? If the charge flows at a constant rate for 40 seconds, what is the current during this time?

5 5 Kirchhoff 1 st Law This law states that the total current entering the junction in a circuit must equal to the total current leaving it. (As shown in the diagram below). 1A 6A 2A 6A 3A Example The figure below shows the currents of 5A and 3A entering a junction in a circuit and a current of 2A leaving. Find the size and the direction of the current of x. 2A 5A x 3A Read only: PFC Page Conductors and insulators Read and make notes on PFC Page How do objects become charge? Figure 12.17: types of resistors

6 6 Resistors Resistors are small devices, which oppose the flow of current in the circuit. Resistors in Series R 1 R 2 We can calculate the total resistance for resistors in series by using: R T = R 1 + R 2 Units: ohms (Ω) Examples Find the equivalent resistor for the following circuit diagrams. a) 2 Ω 3 Ω b) 5Ω 2Ω 1Ω

7 7 Resistors in Parallel R 1 R 2 R 3 We can calculate the total resistance for resistors in parallel by using: 1 = R T R 1 R 2 Examples Find the equivalent resistor for the following circuit diagrams. a) 6Ω 3Ω b) 6Ω 9Ω 3Ω

8 8 Mixed Series and Parallel Combinations of Resistors Examples Find the equivalent resistors for the following circuit diagrams. a) 6Ω 3Ω 3Ω b) 5Ω 7Ω 3Ω

9 9 Ammeters We use the ammeters to measure the current in a circuit; therefore it should not change the amount of current that is flowing. If the ammeter has any resistance it would increase the total resistance in the circuit and reduce the amount of current flowing. Hence the ideal ammeter should have zero resistance. Ammeters are connected in series with the current to be measured. A Voltmeters The voltmeter is used to measure the voltage across a given part of the circuit. The resistance of the voltmeter is very high to prevent any current flowing through it. Any current flowing through the voltmeter means an increase in the current in the circuit hence affecting the reading of the voltmeter. Hence the ideal voltmeter has an infinite resistance and zero current passing through it. The voltmeter is connected in parallel width or across the voltage to be measured. V

10 10 Ohm s Law Ohm s law states that the current through a conductor at a constant temperature is directly proportional to the potential difference between its ends. I V V = constant I where the constant the is the resistance of the conductor R = V I V or V = IR I R Examples a) A current of 4A flows through a headlamp when it is connected to a car battery providing that a voltage of 12 V flows across the headlamp. Calculate the resistance of the headlamp. b) What is the resistance needed to drive a current of 0.2 A through a torchlight lamp of resistance 25 Ω? c) What is the potential difference required to produce a current of 2.5A through a conductor of resistance 12.5 Ω?

11 11 RESISTORS CURRENT VOLTAGE SERIES: V 1 V 2 R 1 R 2 The current is the same in each resistor. I 1 = I 2 = I T The voltage divides up directly according to the each resistance. V T = V 1 + V 2 I T V 1 = I 1 R 1 = I T R 1 V 2 = I 2 R 2 = I T R 2 PARALLEL: I 1 R 1 The current divides according to the inverse ratio of each resistance. The voltage is the same in each resistor. I T I 2 R 2 I T = I 1 + I 2 V 1 = V 2 = V T I 1 = V 1 = V T V T R 1 R 1 I 2 = V 2 = V T R 2 R 2

12 12 Examples 1. Calculate 3A a) total resistance b) total voltage c) voltage across (i) 4Ω (ii) 2Ω resistors 4Ω 2Ω 2. Calculate: 3A a) total resistance b) total voltage c) voltage across (i) 4Ω (ii) 2Ω resistors 2Ω 4Ω 3. Calculate: 15V a) total resistance b) total current c) voltage across 3Ω (i) 2Ω 2Ω (ii) 3Ω (iii) 6Ω 6Ω 4. Calculate: a) total resistance b) total voltage c) voltage across 6Ω 4Ω (i) 4Ω (ii) 2Ω (iii) 30Ω resistors 30Ω 20V

13 13 Power When the energy is converted from one form to another the rate of conversion is defined as power. Units of power: watts (W) They are three basic formulas we can use calculate the power of an electrical circuit. 1. P = IV P I V 2. P = I 2 R P I 2 R 3. P = V 2 V 2 R P R Examples a) An electric fire has a power rating of 3 kw. Calculate the current that will flow through the fire when it is connected to the 240 V mains supply. b) A torch bulb is labelled 2.5 V, 0.3 A. Calculate the power of the bulb and the energy converted in 10 minutes. c) An electric kettle has a heating element rated 2 kw when connected to a 250 V electrical supply. Calculate: (i) the current that would flow when the element was connected to the 250 V supply. (ii) (iii) the resistance of the element. The heat produced by the element in one (1) minute.

14 14 Resistivity Units: ohm meter (Ωm) The resisitivity (ρ) of a material is the numerical value equal to the resistance (R) of the material 1m long with a cross section of 1 m 2. R = ρl A The resistance of a conductor depends on: The thickness of the conductor. (i.e. the resistance of the conductor is inversely proportional to is cross sectional area.) R α 1 A The resistance of the conductor. The resistance of a conductor is directly proportional to the length. R α L The resistance depends on the material that makes up the conductor. Read only: PFC Page 229 Some important characteristics and graphs of resistors. PFC Page Ammeters and voltmeters at work Resistivity Electrical energy and power Read and make notes (include diagrams): PFC Page 255 Simple cell and zinc carbon Dry cell PFC Page 309 Electricity at home Connecting a cable to a power plug Fuses and breakers

1) 10. V 2) 20. V 3) 110 V 4) 220 V

1. The diagram below represents an electric circuit consisting of a 12-volt battery, a 3.0-ohm resistor, R 1, and a variable resistor, R 2. 3. What is the total resistance of the circuit 1) 6.6 Ω 2) 10

Saturday X-tra X-Sheet: 19. Electric circuits

Saturday X-tra X-Sheet: 9 Key Concepts Electric circuits This lesson focuses on the following: Potential Difference Current The resistance of a conductor Ohm s Law and circuit calculations Terminology

Electric Currents. Electric Potential Energy 11/23/16. Topic 5.1 Electric potential difference, current and resistance

Electric Currents Topic 5.1 Electric potential difference, current and resistance Electric Potential Energy l If you want to move a charge closer to a charged sphere you have to push against the repulsive

Science AS90191 Describe Aspects of Physics.

Circuits and components Science AS90191 Describe Aspects of Physics. An electric current is the movement of electrons (negatively charged particles). A circuit is made up of components connected together

OHM S LAW 05 AUGUST 2014

OHM S LAW 05 AUGUST 2014 In this lesson, we: Current Lesson Description Revise the definitions of current, potential difference and emf Explore Ohm s law Identify the characteristics of ohmic and non-ohmic

physics 112N current, resistance and dc circuits

physics 112N current, resistance and dc circuits current! previously we considered electrostatic situations in which no E-field could exist inside a conductor! now we move to the case where an electric

CHAPTER12. Electricity. Multiple Choice Questions. Fig. 12.1

CHAPTER12 Electricity Multiple Choice Questions 1. A cell, a resistor, a key and ammeter are arranged as shown in the circuit diagrams of Figure12.1. The current recorded in the ammeter will be Fig. 12.1

[2]...[1] [3]

High Demand Questions QUESTIONSHEET 1 (a) In the circuit below, lamps P and Q are identical. The reading on the ammeter is 3A. The cell shown is of emf. 6V. A P Q Calculate the current that passes through

Chapter 11- Electricity

Chapter 11- Electricity Course Content Definition of Electricity Circuit Diagrams Series and Parallel Circuits Calculating total resistances Measurement of Electricity Ammeters and Voltmeters Ohm s Law

Series and Parallel Circuits

Series and Parallel Circuits Components in a circuit can be connected in series or parallel. A series arrangement of components is where they are inline with each other, i.e. connected end-to-end. A parallel

B. 1.3 Ω D Ω (Total 1 mark)

Practice Test: 30 marks (39 minutes) Additional Problem: 5 marks (37 minutes) 1. One electronvolt is equal to A. 1.6 10 19 C. B. 1.6 10 19 J. C. 1.6 10 19 V. D. 1.6 10 19 W.. In the circuit below, which

Series & Parallel Circuits Challenge

Name: Part One: Series & Parallel Circuits Challenge 1. Build a circuit using two batteries and two light bulbs in a way to illuminate the two light bulbs so that if either light bulb is disconnected,

What will we learn in this chapter?

Chapter 19: Current, resistance, circuits What will we learn in this chapter? What are currents? Resistance and Ohm s law (no, there are no 3 laws). Circuits and electric power. Resistors in series and

Circuits. Page The diagram below represents a series circuit containing three resistors.

Name: Circuits Date: 1. Which circuit segment has an equivalent resistance of 6 ohms? 4. The diagram below represents a series circuit containing three resistors. 2. Base your answer to the following question

The content contained in sections 1 4, 6 9, 11 13, and 15 of chapter 20 of the textbook is included on the AP Physics B exam.

hapter 0 Electric ircuits hapter 0 ELETR RUTS PREVEW onventional current is the flow of positive charges though a closed circuit. The current through a resistance and the voltage which produces it are

MC Electricity Resistors Review

2. In the circuit shown above, what is the value of the potential difference between points X and Y if the 6 volt battery has no internal resistance? (A) 1 V (B) 2 V (C) 3 V (D) 4 V (E) 6V 8. The circuit

Circuits-Circuit Analysis

Base your answers to questions 1 through 3 on the information and diagram below. 4. A 9-volt battery is connected to a 4-ohm resistor and a 5-ohm resistor as shown in the diagram below. A 3.0-ohm resistor,

EDEXCEL NATIONAL CERTIFICATE/DIPLOMA UNIT 5 - ELECTRICAL AND ELECTRONIC PRINCIPLES NQF LEVEL 3 OUTCOME 1 - D.C. CIRCUITS

EDEXCEL NATIONAL CERTIFICATE/DIPLOMA UNIT 5 - ELECTRICAL AND ELECTRONIC PRINCIPLES NQF LEVEL 3 OUTCOME - D.C. CIRCUITS Be able to use circuit theory to determine voltage, current and resistance in direct

Electrical Fundamentals Module 3: Parallel Circuits

Electrical Fundamentals Module 3: Parallel Circuits PREPARED BY IAT Curriculum Unit August 2008 Institute of Applied Technology, 2008 ATE310- Electrical Fundamentals 2 Module 3 Parallel Circuits Module

Electrostatics. Electrostatics Version 2

1. A 150-watt lightbulb is brighter than a 60.-watt lightbulb when both are operating at a potential difference of 110 volts. Compared to the resistance of and the current drawn by the 150-watt lightbulb,

7. What is the current in a circuit if 15 coulombs of electric charge move past a given point in 3 seconds? (1) 5 A (3) 18 A (2) 12 A (4) 45 A

1. Compared to the number of free electrons in a conductor, the number of free electrons in an insulator of the same volume is less the same greater 2. Most metals are good electrical conductors because

Unit 7: Electric Circuits

Multiple Choice Portion 1. The diagram below shows part of an electrical circuit. Unit 7: Electric Circuits 4. A 12 V battery supplies a 5.0 A current to two light bulbs as shown below. What are the magnitude

PHYSICS 111 LABORATORY Experiment #3 Current, Voltage and Resistance in Series and Parallel Circuits

PHYSCS 111 LABORATORY Experiment #3 Current, Voltage and Resistance in Series and Parallel Circuits This experiment is designed to investigate the relationship between current and potential in simple series

Q1. (a) Complete the sentence below to name the instrument used to measure electrical current.

Q. (a) Complete the sentence below to name the instrument used to measure electrical current. The instrument used to measure electrical current is called... () (b) In the diagram below each box contains

Circuits Review KEY Interpreting Diagrams Use the diagram below to answer the following questions.

Circuits Review KEY Interpreting Diagrams Use the diagram below to answer the following questions. 1. Look at the arrows which indicate the direction of the flow of electrons. Label the negative and the

Section 6. Current, Voltage, and Resistance in Parallel and Series Circuits: Who s in Control? What Do You See? What Do You Think?

Section 6 Current, Voltage, and Resistance in Parallel and Series Circuits: Who s in Control? What Do You See? Learning Outcomes In this section, you will ssemble a switch in a circuit with parallel components

Chapter 13: Electric Circuits

Chapter 13: Electric Circuits 1. A household circuit rated at 120 Volts is protected by a fuse rated at 15 amps. What is the maximum number of 100 watt light bulbs which can be lit simultaneously in parallel

Electric Circuits Review

Electric Circuits Review 1. Which of the following statements are true about electric current? Circle all that apply. a. Electric current is measured in units of Amperes. b. Electric current is defined

Lecture PowerPoints. Chapter 19 Physics: Principles with Applications, 7th edition Giancoli

Lecture PowerPoints Chapter 19 Physics: Principles with Applications, 7th edition Giancoli This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching

Chapter 13 Electric Circuits

Chapter 13 Electric Circuits What is Electric Current? How does it resemble the flow of water in a pipe? Can you get a flashlight bulb to light, with a battery and a single wire? Electric Circuits and

What is the direction of a compass needle placed at point A?

SAMPLE QUIZ: COVERAGE OHM S LAW CIRCUIT ANALYSIS RESISTANCE ELECTRICAL POWER MAGNETISM AND ELECTROMAGNETISM MAGNETISM: 1. In order to produce a magnetic field, an electric charge must be 1. stationary

People s Physics Book

The Big Ideas: The name electric current is given to the phenomenon that occurs when an electric field moves down a wire at close to the speed of light. Voltage is the electrical energy density (energy

Chapter 12: Current Electricity

Chapter 12: Current Electricity And God said, Let there be light and there was light, but the electricity board said He would have to wait until Thursday to be connected. Spike Milligan Objectives 1. Define

Question Bank. Electric Circuits, Resistance and Ohm s Law

Electric Circuits, Resistance and Ohm s Law. Define the term current and state its SI unit. Ans. The rate of flow of charge in an electric circuit is called current. Its SI unit is ampere. 2. (a) Define

1 ANSWERS to CIRCUITS 1. The speed with which electrons move through a copper wire is typically 10-4 m s -1. a. Explain why is it that the electrons cannot travel faster in the conductor? b. Explain why

Electrical Power. How do you calculate electrical power? 14.3

. Name: Date: Electrical Power 14.3 How do you calculate electrical power? In this skill sheet you will review the relationship between electrical power and Ohm s law. As you work through the problems,

Direct-Current Circuits

Chapter 13 Direct-Current Circuits In This Chapter: Resistors in Series Resistors in Parallel EMF and Internal Resistance Kirchhoff s Rules Resistors in Series The equivalent resistance of a set of resistors

Fundamentals of Direct Current Circuits

Fundamentals of Direct Current Circuits Course No: E06-001 Credit: 6 PDH A. Bhatia Continuing Education and Development, Inc. 9 Greyridge Farm Court Stony Point, NY 10980 P: (877) 322-5800 F: (877) 322-4774

EMF & INTERNAL RESISTANCE 28 JULY 2015 Section A: Summary Notes

EMF & INTERNAL RESISTANCE 28 JULY 2015 Section A: Summary Notes Internal Resistance The emf of a cell is the maximum amount of energy which the cell can supply. When the cell is delivering current, the

National 5 Physics. Language Wikipedia. Electricity

National 5 Physics Catlin.Fatu@English Language Wikipedia Electricity Throughout the Course, appropriate attention should be given to units, prefixes and scientific notation. tera T 10 12 x 1,000,000,000,000

Part 1. Part 1. Electric Current. and Direct Current Circuits. Electric Current. Electric Current. Chapter 19. Electric Current

Electric Current Electric Current and Direct Current Circuits Chapter 9 Resistance and Ohm s Law Power in Electric Circuits Direct Current Circuits Combination Circuits Real life is mostly dynamic Part

Circuit symbol. Each of the cells has a potential difference of 1.5 volts. Figure 1. Use the correct answer from the box to complete the sentence.

Q.(a) Draw one line from each circuit symbol to its correct name. Circuit symbol Name Diode Light-dependent resistor (LDR) Lamp Light-emitting diode (LED) (3) Figure shows three circuits. The resistors

Chapter 2 Objectives

Chapter 2 Engr228 Circuit Analysis Dr Curtis Nelson Chapter 2 Objectives Understand symbols and behavior of the following circuit elements: Independent voltage and current sources; Dependent voltage and

Ohm s Law & Series Circuit

Open the TI-Nspire document Ohms_Law_&_Series_Circuit.tns. We all use and rely on electric circuits every day by flipping a switch, turning up the volume, or operating a computer or calculator. Even the

Chapter 23 Practice Problems, Review, and Assessment

Section 1 Simple Circuits: Practice Problems 1. Three 22-Ω resistors are connected in series across a 125-V generator. What is the equivalent resistance of the circuit? What is the current in the circuit?

Electricity and Water Analogy

[ Assignment View ] [ Eðlisfræði 2, vor 2007 25. Current, Resistance, and Electromagnetic Force Assignment is due at 2:00am on Wednesday, February 14, 2007 Credit for problems submitted late will decrease

Objectives 200 CHAPTER 4 RESISTANCE

Objectives Explain the differences among conductors, insulators, and semiconductors. Define electrical resistance. Solve problems using resistance, voltage, and current. Describe a material that obeys

Physics Worksheet Electric Current Section: Name:

Do Now: Water Flow vs. Electric Current Models: f an electric circuit consists of wires, a battery and a light bulb, please compare the water flow in the following picture to the electric current in a

4 Electrical Quantities and Ohm s Law

Ch a pt er 4 Electrical Quantities and Ohm s Law Learning Outcomes Define electric current, voltage, resistance, power, and energy, and list the unit of measurement of each. Identify the essential parts

AP1 Electricity. 1. A student wearing shoes stands on a tile floor. The students shoes do not fall into the tile floor due to

1. A student wearing shoes stands on a tile floor. The students shoes do not fall into the tile floor due to (A) a force of repulsion between the shoes and the floor due to macroscopic gravitational forces.

Section 2. Physics. Electricity Mechanics Nuclear Physics Waves

Section 2 Physics Electricity Mechanics Nuclear Physics Waves 1 Electricity Electricity is a topic that always comes up in every single BMAT paper without fail, and often has multiple questions associated

Duration of resource: 23 Minutes. Year of Production: Stock code: VEA12041

ADDITIONAL RESOURCES We use electrical circuits every day. In the home, the car, at work and school they are a vital part of our lives. This program covers the basics of electrical circuits in detail.

Clicker Question. Which of the two arrangements shown has the smaller equivalent resistance between points a and b?

Which of the two arrangements shown has the smaller equivalent resistance between points a and b? A. the series arrangement B. the parallel arrangement C. The equivalent resistance is the same for both

Preview of Period 13: Electrical Resistance and Joule Heating

Preview of Period 13: Electrical Resistance and Joule Heating 13.1 Electrical Resistance of a Wire What does the resistance of a wire depend upon? 13.2 Resistance and Joule Heating What effect does resistance

3_given a graph of current_voltage for a resistor, determine the resistance. Three resistance R1 = 1.0 kω, R2 = 1.5 kω, R3 = 2.

Ohm s Law Objectives: 1_measure the current_voltage curve for a resistor 2_construct a graph of the data from objective 1 3_given a graph of current_voltage for a resistor, determine the resistance Equipment:

More Concepts. I = dq. Current is the rate of flow of charge around a circuit.

RC Circuits In this presentation, circuits with multiple batteries, resistors and capacitors will be reduced to an equivalent system with a single battery, a single resistor, and a single capacitor. Kirchoff's

Electric Circuits. 1 Electric Current and Electromotive Force

1 Electric Current and Electromotive Force The flow of electric charges: Electric currents power light bulbs, TV sets, computers etc. Definition of electric current: The current is the rate at which charge

Henry Lin, Department of Electrical and Computer Engineering, California State University, Bakersfield Lecture 3 (Electric Circuits) July 16 th, 2013

Henry Lin, Department of Electrical and Computer Engineering, California State University, Bakersfield Lecture 3 (Electric Circuits) July 16 th, 2013 1 What is an electrical circuit? An electrical network

Electric Circuits: Batteries and Resistors

Electric Circuits: Batteries and Resistors James H Dann, Ph.D. Say Thanks to the Authors Click http://www.ck12.org/saythanks (No sign in required) To access a customizable version of this book, as well

Level 2 Physics: Demonstrate understanding of electricity and electromagnetism

Level 2 Physics: Demonstrate understanding of electricity and electromagnetism Static Electricity: Uniform electric field, electric field strength, force on a charge in an electric field, electric potential

DC Circuits. 3. Three 8.0- resistors are connected in series. What is their equivalent resistance? a c b. 8.0 d. 0.13

DC Circuits 1. The two ends of a 3.0- resistor are connected to a 9.0-V battery. What is the current through the resistor? a. 27 A c. 3.0 A b. 6.3 A d. 0.33 A 2. The two ends of a 3.0- resistor are connected

Two kinds of electrical charges

ELECTRICITY NOTES Two kinds of electrical charges Positive charge Negative charge Electrons are negatively charged Protons are positively charged The forces from positive charges are canceled by forces

The current that flows is determined by the potential difference across the conductor and the resistance of the conductor (Ohm s law): V = IR P = VI

PHYS1000 DC electric circuits 1 Electric circuits Electric current Charge can move freely in a conductor if an electric field is present; the moving charge is an electric current (SI unit is the ampere

11 Internal resistance, series and parallel circuits, and the potential divider Exam practice questions

Pages 68-72 Start by working out the resistance of each of the combinations: W: In series R = R + R 2 + R 3 = 5 Ω + 5 Ω + 5 Ω = 45 Ω X: Start by adding the two series resistors: 5 Ω + 5 Ω = 30 Ω Then combine

TOPIC 4 ELECTRIC CIRCUITS

IGCSE Physics 0625 notes Topic 4: Electric Circuits 1 TOPIC 4 ELECTRIC CIRCUITS ELECTRIC CURRENT (I): Current (I) is defined as the rate of flow of electric charge (Q) in an electric conductor. The unit

Electric Current and Current Density. Ohm s Law: resistance and resistors

CH25: Current, Resistance and Electromotive Force Electric Current and Current Density Drift Velocity Resistivity Ohm s Law: resistance and resistors Circuits Connection and emf Energy and Power in Circuits

Current and resistance

Current and resistance Electrical resistance Voltage can be thought of as the pressure pushing charges along a conductor, while the electrical resistance of a conductor is a measure of how difficult it

ELECTRICAL CIRCUITS. Electrical Circuits

Electrical Circuits A complete path, or circuit, is needed before voltage can cause a current flow through resistances to perform work. There are several types of circuits, but all require the same basic

Electrical Circuits I Lecture 1

Electrical Circuits I Lecture Course Contents Basic dc circuit elements, series and parallel Networks Ohm's law and Kirchoff's laws Nodal Analysis Mesh Analysis Source Transformation

Series,"Parallel," and"series." Parallel"Circuits"

chapter 25 Series,"Parallel," and"series." Parallel"Circuits" FIGURE 25.1 A series circuit with three bulbs. All current flows through all resistances (bulbs). The total resistance of the circuit is the

Electrical Circuit Calculations

Electrical Circuit Calculations Series Circuits Many circuits have more than one conversion device in them (i.e. toaster. heater. lamps etc.) and some have more than one source of electrical energy. If

Q1. (a) The diagram shows the voltage-current graphs for three different electrical components.

Q. (a) The diagram shows the voltage-current graphs for three different electrical components. Which one of the components A, B or C could be a 3 volt filament lamp? Explain the reason for your choice...................

Chapter 11. Circuits

Chapter 11 Circuits 376 377 AP Physics Multiple Choice Practice Circuits 1. Multiple Correct. Which two arrangements of resistors shown above have the same resistance between the terminals? Select two

Series and Parallel Circuits

Series and Parallel Circuits Direct-Current Series Circuits A series circuit is a circuit in which the components are connected in a line, one after the other, like railroad cars on a single track. There

EE301 RESISTANCE AND OHM S LAW

Learning Objectives a. Describe the concept of resistance b. Use Ohm s law to calculate current, voltage, and resistance values in a circuit c. Discuss the difference between an open circuit and a short

Conceptual. Problems:

Conceptual 2. 4. A sht circuit can develop when the last bit of insulation frays away between the two conducts in a lamp cd. Then the two conducts touch each other, creating a low resistance path in parallel

CIRCUITS WORKSHEET. 1. Determine the equivalent (total) resistance for each of the following circuits below.

CCUTS WOKSHEET. Determine the uivalent (total) resistance for each of the following circuits below. 7 5 70. 59 59 70 5 7. Determine the total voltage (electric potential) for each of the following circuits

Electricity CHAPTER 12 12.1 ELECTRIC CURRENT AND CIRCUIT

CHAPTER 12 Electricity Electricity has an important place in modern society. It is a controllable and convenient form of energy for a variety of uses in homes, schools, hospitals, industries and so on.

CURRENT ELECTRICITY PREVIOUS EAMCET QUESTIONS ENGINEERING

Current lectricity CUNT LCTICITY PVIOUS AMCT QUSTIONS NGINING. In the circuit shown below, a voltmeter of internal resistance, when connected across B and C reads 00/ volts. Neglecting the internal resistance

Series and Parallel Wiring

Series and Parallel Wiring Thus far, we have dealt with circuits that include only a single device, such as a light bulb. There are, however, many circuits in which more than one device is connected to

Experiment #6, Series and Parallel Circuits, Kirchhoff s Laws

Physics 182 Spring 2013 Experiment #6 1 Experiment #6, Series and Parallel Circuits, Kirchhoff s Laws 1 Purpose Our purpose is to explore and validate Kirchhoff s laws as a way to better understanding

Note-A-Rific: Characteristics

Note-A-Rific: Characteristics Any path along which electrons can flow is a circuit. For a continuous flow of electrons, there must be a complete circuit with no gaps. A gap is usually an electric switch

Chapter 21 Electric Current and Direct-Current Circuit

Chapter 21 Electric Current and Direct-Current Circuit Outline 21-1 Electric Current 21-2 Resistance and Ohm s Law 21-3 Energy and Power in Electric Circuit 21-4 Resistance in Series and Parallel 21-5

Chapter 6. Experiment 4: Electric Currents and Circuits. 6.1 Introduction The Electric Current

Chapter 6 Experiment 4: Electric Currents and Circuits 6.1 Introduction The resistance to the flow of an electric current is essential in the design of electronic devices and electric circuits generally.

EMF and Terminal Voltage Resistors in Series and Parallel Kirchhoff s Rules EMFs in Series and Parallel; Charging a Battery Circuits with Capacitors

Chapter 19 DC Electrical Circuits Topics in Chapter 19 EMF and Terminal Voltage Resistors in Series and Parallel Kirchhoff s Rules EMFs in Series and Parallel; Charging a Battery Circuits with Capacitors

Student Content Brief Advanced Level Electric Circuits Background Information There are a variety of forces acting on the body of the Sea Perch. One important force is pushing electrons through the wires

Electric Circuits. AP Physics C

Electric Circuits AP Physics C Potential Difference oltageemf n a battery, a series of chemical reactions occur in which electrons are transferred from one terminal to another. There is a potential difference

Experiment #5, Series and Parallel Circuits, Kirchhoff s Laws

Physics 182 Summer 2013 Experiment #5 1 Experiment #5, Series and Parallel Circuits, Kirchhoff s Laws 1 Purpose Our purpose is to explore and validate Kirchhoff s laws as a way to better understanding

Physics Worksheet Electric Circuits Section: Name: Series Circuits

Do Now: (1) What is electric circuit? (2) Convert the following picture into schematic diagram. Series Circuits 4. Label every component of the circuit; identify each of the voltage and current. 5. Relation

Resistors in Series and Parallel

Resistors in Series and Parallel INTRODUCTION Direct current (DC) circuits are characterized by the quantities current, voltage and resistance. Current is the rate of flow of charge. The SI unit is the

Kirchhoff's Rules and Applying Them

[ Assignment View ] [ Eðlisfræði 2, vor 2007 26. DC Circuits Assignment is due at 2:00am on Wednesday, February 21, 2007 Credit for problems submitted late will decrease to 0% after the deadline has passed.

(a) Between A and C, as in Figure 1. Figure (2) (b) Between A and B, as in Figure 2. Figure (3) (Total 5 marks)

Q1. Four resistors, each having resistance of 50 Ω, are connected to form a square. A resistance meter measured the resistance between different corners of the square. Determine the resistance the meter

Kirchhoff s Laws. Kirchhoff's Law #1 - The sum of the currents entering a node must equal the sum of the currents exiting a node.

Kirchhoff s Laws There are two laws necessary for solving circuit problems. For simple circuits, you have been applying these equations almost instinctively. Kirchhoff's Law #1 - The sum of the currents

PHY 101 Lab 7 on Electric circuits: Direct current circuits Your name: Other team members:

PHY 101 Lab 7 on Electric circuits: Direct current circuits Your name: Other team members: Goals: To explore the basic principles of electric circuits, and how to measure them. Materials: Electrical resistors

Chapter 23 Series and Parallel Circuits

Chapter 23 Series and Parallel Circuits Chapter 23 Series and Parallel Circuits In this chapter you will: Distinguish among series circuits, parallel, and seriesparallel combinations, and solve problems

Σ I in = Σ I out E = IR 1 + IR 2 FXA 2008 KIRCHHOFF S LAWS 1. Candidates should be able to : LAW 1 (K1)

UNT G482 Module 3 2.3.1 Series & Parallel Circuits Candidates should be able to : KRCHHOFF S LAWS 1 LAW 1 (K1) State Kirchhoff s second law and appreciate that it is a consequence of conservation of energy.

Resistance is defined as a measure of the ease of current flow, and is the ratio of the potential difference to the current - Ohm s law.

Resistance and Ohms Law When we have a fixed potential difference then the electric field will also be fixed and therefore there will be a steady electric force on the charge carriers (electrons) - this

s_5xut Page 1 Physics Samples

Physics Samples E&M Unit 1. Two metal spheres having charges of +4.0 x 10 6 coulomb and +2.0 x 10 5 coulomb, respectively, are brought into contact and then separated. After separation, the charge on each