RL Circuits - Inductors & Resistors

This physics video tutorial provides a basic introduction into RL circuits which are made of inductors and resistors. It explains how to calculate the instantaneous current at any time as well as the maximum current after the switch has been closed for a long time. It discusses how to calculate the time constant given the inductance and the resistance and how to determine how many time constants is required for the inductor to be 99.4% charged. This video explains how to calculate the voltage across the inductor and the resistor as well as the battery. It explains how to determine the instantaneous rate at which energy is being consumed by the resistor and the inductor. The emf induced by the inductor is dependent on the rate at which the current is changing in the circuit. This video contains plenty of examples and practice problems.

Magnetism - Review:

Faraday's Law of Electromagnetic Induction:

Lenz's Law - Induced Current:

Induced EMF In Moving Conductor:

Electric Generators & Induced EMF:

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Counter EMF of DC Motors:

Transformers - Physics Problems:

Mutual Inductance & Solenoids:

Self-Inductance of Inductors & Coils:

How To Make an Electromagnet:

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Faraday's & Lenz's Law of Electromagnetic Induction:

Energy Stored In an Inductor:

RL Circuits - Inductors & Resistors:

Final Exams and Video Playlists:

Full-Length Videos and Worksheets:

[ncedwards]

Last minute cramming. Fell asleep right at the end. Woke up to a loud af chicken nugget commercial. This is my life now.

[justinakabamba]

I always look for your videos, they are simple and easy to understand. Such teachers like you makes me love physics more.

[joshualee]

This simplified what my teacher overcomplicated. I appreciate how concise and simple you made all of this

[mikefaraday]

Dude, you're a genius. I planned to skip these questions in my upcoming FE exams but then I decided to watch your video and lo and behold, you've made it so easy. and even explained what's not in the question. Thank you.

[mrinfamous]

Got an Electrical engineering midterm in 24 hours. Thank You 🙏

[rykezarr]

Love this guy! he's far better than khan academy with explanations!

[haimlot]

Many many summer's ago i stumbled upon this matter, keep up with those lectures bless you and your family and upbringing.

[odewayemayomi]

If not because of JG video, I don't know where I'll be today. Always teach from scratch until someone understand it. I always had A in school anytime I consult JG videos. You are not better than the rest but Best among the best.

[jeremymcdonald]

I have learned more from the organic chemistry tutor than I have in any lecture hall.

[reedwillette]

i know it's an old vid but you have excellent talent! I'll crush the test thanks to you

[Hopeless_and_Forlorn]

Problem at 4:30--the current cannot decrease exponentially as stated when the switch is opened because open switch = open circuit = zero current, leading one to conclude that current decreases to zero instantaneously. In practice, as current decreases at a very high rate when switch is opened, di/dt is very high, energy stored in coil's magnetic field is discharged into circuit at a very high rate, a very high voltage is developed in the coil opposing the drop in current, that voltage opposes the battery voltage and is many times higher, and the air between the opening switch contacts is ionized, allowing a spark of current to flow in the direction opposite to the original current to dissipate the power supplied by the inductor. You have here the basis of the battery-powered automotive ignition circuit.

[MariyaShalashova]

You saved my degree. I am forever grateful.

[successthruknowledge]

Another great set of examples helping us to understand the intricacies of these calculations. I don't yet understand how capacitors and inductors differ in their purposes for a single circuit. When do you use one or the other for a single circuit and why?

[mondeinnocent]

Things gets simplified here. Thank you very much

[uuitgaurav]

I have whole elcetro mechanics in back log and i have exam on this Friday today is tuesday. I gonna put my bet on you.

[drewross]

Exam in exactly 24 hours, I’d say I’m on the lower end of procrastination compared to some here, but I had to spend the last 5 days Nodal, Mesh, Linearity, Max Power, Thevenin’s, Norton’s, Source Transformation, Op-Amps, Capacitors, RC Circuits (still working on getting that down) because I took this entire semester for granted aaaand now I’m here. Wish me luck lmao

[ucnongvan]

thank you so much for your informative tutorials

[HitAndMissLab]

@"The Organic Chemistry Tutor" - Can you possibly explain me one thing that I find hard to understand.



Lets say we have an inducting coil, but it is make of a super-conductor. We fill that super-conducting coil with current and store energy in magnetic field that is created. We unplug the coil from the current source and current flows forever, because there is no resistance.



Now comes the difficult part I don't understand: since now energy is stored in a magnetic field, and stored energy is a state of higher potential, wouldn't be normal to expect magnetic field to want to collapse back to zero and in process coil current will fade away to zero, as well?


Essentially, never mind that resistance in super-conductor is zero, the magnetic field would want to collapse, regardless of what resistance is, because it's on a higher potential?

[julescovers]

Thank you, oh my god. Also 10/10 accent

[mwzd-]

he said LR rather than RL but still managed to understand what a guy