Physics: Intro to Electricity & Magnetism

Name: Physics: Intro to Electricity & Magnetism
Rating: 4.6 (1445 reviews)

A fun and easy way to boost your physics grades

Created byScott Redmond

Last updated 10/2016

English

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What you'll learn

Explain how objects get electrically charged, both with and without touching other charged objects.
Set up and solve problems involving Coulomb's Law
Explain how the electric field is independent of the test charge
Solve problems involving electric charges moving through electric fields
Determine the electric fields created by point charges and charge distributions

Course content

9 sections • 46 lectures • 3h 45m total length

Course Introduction1:43
Welcome to the course! My #1 goal is to boost your physics grade, and I would love to hear your feedback on what I can do to make this course even better for you.
Practice Activities0:16
Here are some downloadable PDF files with practice questions that you can use to test your understanding.

Introduction to Electric Charge3:41
The electric charge is the absolute first thing to master when learning electricity and magnetism. This lecture will quickly show you the key ideas so you can go smoothly through the rest of your course.
Conductors, Insulators, and Charging6:44
Conductors are quite different from insulators, and this lecture quickly shows you how. I also show you how objects can become charged, including a description of how to use the triboelectric series to determine which object will become positive (or negative) when two materials are rubbed together.
Charge Polarization4:49
Charge polarization, which occurs when positive and negative charges are separated, explains how insulators can experience an electric force and sets up the foundation for understanding charging by induction in the next lecture.
Charging by Induction2:58
When you charge an object by induction, you are charging it by using a different charged object but without actually touching the charged object. Many students misunderstand how this works, and this lecture will set you straight so you can ace this question on your exam.
Coulomb's Law5:43
Coulomb's Law tells us how to calculate the electric force between point charges. This idea becomes a cornerstone for the rest of the course because the electric force just keeps coming back.

Introduction to Electric Fields and the Test Charge10:33
Mastering the electric field, and the idea of the test charge, is one of the most important things you can do to ace your electricity and magnetism course. This lecture builds heavily on the comparison of the force of gravity and the idea of a gravitational field, to help you relate the electric force and field to something that's easier to grasp.
Electric Field of a Point Charge10:34
In this lecture, you will see two ways to determine the electric field caused by a point charge. Later in your course, you will use this idea to find the electric field from many point charges.
Electric Field Lines2:42
Electric field lines are used to visualize the direction of the electric field caused by one or more electric charges. This is a nice quick lecture, since it's a fairly straightforward idea.
Motion of a Point Charge in a Constant Uniform Electric Field6:28
When you place a moving point charge inside a constant uniform electric field, the result is just like projectile motion, with two big differences! First, the electric force can be in any direction - unlike gravity, which is typically vertically down. Second, the electric force direction depends on whether the charge is positive or negative - unlike gravity, in which masses are always attracted to each other.
Electric Field of a Continuous Charge Distribution9:37
Explore how to use calculus to determine the electric field of a continuous charge distribution by considering each tiny piece of charge, dq, as a point charge.
Also check the external resources for YouTube videos showing how to derive the electric field of a ring and a disk of uniform charge.
Introducing the Permittivity Constant1:16
The permittivity constant seems to complicate things now, but it will be used much more in later parts of the course.

Introduction to Gauss' Law1:37
Learn the high-level aspects of Gauss' Law that we'll dive into in the following lectures.
What is Flux?4:58
Gauss' Law and Applications to Charged Insulators2:25
Apply Gauss's law by choosing a closed Gaussian surface to relate net electric flux to the enclosed charge, simplifying field calculations for charged insulators and conductors.
Three Key Ideas about Conductors in Electrostatic Equilibrium13:36

Introduction to Electric Potential and Electric Potential Energy2:08
Explore how electric potential relates to electric potential energy, both scalars, starting with point charges and then systems of charges. Learn equipotential curves, perpendicular to field lines.
Electric Potential4:00
Electric Potential Energy3:38
Electric Potential Energy of a System of Point Charges4:11
Bring in charges one by one to build the total potential energy from pairwise interactions, computed as k Q_i Q_j / r_ij and released as kinetic energy.
Equipotential Curves4:35
Electric Field -> Potential Difference2:32
Learn how equipotential curves relate to electric field lines. Apply delta V = -∫ e·ds to compute potential changes along a path, with a uniform-field simplification -e·Δs.
Potential Difference -> Electric Field4:03
Compute the electric field from a potential function via negative partial derivatives along x, y, and z: E = -∇V, with Ex = -dV/dx, Ey = -dV/dy, Ez = -dV/dz.

Introduction to DC Circuits Without Capacitors2:02
Explore dc circuits without capacitors, identifying wires, resistors, switches, and meters. Learn to use an ammeter and voltmeter, and apply equivalent resistance in series and parallel via Kirchoff's laws.
Circuit Elements and Electric Current6:41
Review circuit elements such as wires, resistors, switches, capacitors, and inductors, and learn how a voltage source drives current while voltmeters and ammeters measure voltage and current.
Using a Voltmeter and/or Ammeter5:50
Use a voltmeter to measure potential difference across circuit elements with correct lead polarity, and place an ammeter in series by breaking the wire to measure current.
Equivalent Resistance - Series and Parallel7:41
Identify the equivalent resistance and distinguish series and parallel resistor configurations. Use color-coding to determine when resistors share wires, then compute R_eq by series sum or parallel inverse sum.
Kirchoff's Current Law (Junction Rule)3:37
Explore Kirchoff's current law, the junction rule, where current in equals current out at a junction, with equations like sum in minus sum out equals zero.
Kirchoff's Voltage Law (Loop Rule)11:00
Ideal vs Real emf2:55
Contrast ideal and real emf, noting real emf includes resistance. Draw the circuit with this resistance, apply emf minus i r equals zero, and connect brightness to emf and current.

Introduction to Capacitors and Capacitance1:07
Explore capacitors in DC circuits by defining capacitance and equivalent capacitance, including parallel plate capacitors and energy stored. Examine RC circuits, charging and discharging, time constants, and dielectrics with equations.
What is a Capacitor? What about Capacitance?6:47
Equivalent Capacitance - Capacitors in Series7:53
Equivalent Capacitance - Capacitors in Parallel3:31
Learn how capacitors in parallel share the same voltage and sum their charges to form an equivalent capacitance equal to the sum of the individual capacitances.
Special Case: Parallel Plate Capacitor5:04
Derive the parallel plate capacitor by treating plates as infinite planes when A is much larger than d, obtaining C = ε0 A / d.
Energy Stored in a Capacitor6:24
Explore how energy stored in a capacitor is derived from conservation of energy, showing U = Q^2/(2C) and U = 1/2 C V^2 during charging.
RC Circuits (Charging and Discharging)11:30
Explore charging and discharging of RC circuits, noting exponential current decay and voltage rise; see uncharged capacitors act like wires, fully charged like opens, with tau = RC.
Dielectrics6:56
Explore dielectrics in capacitors: inserting an insulator polarizes atoms, reduces net field, and increases capacitance, enabling more charge at the same voltage.

Introduction to Magnetic Fields1:27
Magnetic Field Lines2:49
Examine magnetic field lines, denoted by B with arrow and measured in tesla, showing that line density reflects field magnitude and that lines run from north to south.
Magnetic Force on an Electric Charge2:56
Explore the magnetic force on a moving charge, perpendicular to velocity and the magnetic field, with magnitude proportional to q, v, B, and sin theta via the cross product.
Motion of a Charged Particle in a Constant Uniform Magnetic Field8:44
Analyze how a charged particle moves in a uniform magnetic field, showing parallel, perpendicular, and helical motion; derive radius and period for circular motion and introduce pitch.
Magnetic Force on a Current-Carrying Wire4:28
Explore the magnetic force on a current-carrying wire, deriving the cross-product form of the force from the drift velocity of electrons in a magnetic field and the right-hand rule.

Requirements

Students should already understand the following math concepts: trigonometry, vectors, algebraic manipulation, and basic calculus derivatives and integrals.

Description

This course introduces the fundamental concepts of electric charge, electric force, and electric fields, using hand-drawn animations. This is excellent for students who are taking a physics class but need extra help understanding the material, whether it's because your teacher is hard to understand, you miss some lectures, or you'd simply like a fresh perspective.

Master the Core Concepts of Electricity & Magnetism in this Introductory Course

Learn the fundamental concepts, electric charge and electric field, that help the rest of the course go more smoothly.
Understand how charging by induction really works so you can guarantee you'll get those grades on your unit test.
Explain how the electric field is independent of the test charge.

Solve problems involving electric charges moving through electric fields.

Boost Your Grades in Your Electricity & Magnetism Physics Course

This course will boost your physics grades by clearly explaining the fundamental introductory concepts and giving insight into what sorts of difficulties professors like to introduce in exams. Here, you will learn all about the first two chapters, on electric charge and electric fields, of a standard physics course on electricity and magnetism. The course author uses his experience teaching college physics to highlight the key ideas and dangerous misconceptions while having some fun with hand-drawn animations and some goofy examples.

At the end of this course, you will have a solid understanding of electric charges and electric fields, and you will know what mistakes to avoid so you can get better grades on your next test or exam.

Who this course is for:

This course is ideal for students who are already taking a physics course and need another perspective, or who need to catch up on missed lectures.
This course is also helpful for students who plan to take electricity and magnetism in the near future and want a sneak preview of what's coming.
This course can also be helpful for new physics teachers who are looking for ideas of how to present the concepts in different ways.

Physics: Intro to Electricity & Magnetism

What you'll learn

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Course content

Introduction2 lectures • 2min

Electric Charge and Electric Force5 lectures • 24min

Electric Fields6 lectures • 41min

Gauss' Law4 lectures • 23min

Electric Potential7 lectures • 25min

DC Circuits Without Capacitors7 lectures • 40min

DC Circuits With Capacitors8 lectures • 49min

Magnetic Field5 lectures • 20min

What's Next?2 lectures • 2min

Requirements

Description

Who this course is for: