# Physics Video Lectures

Here you will find 20 free physics video lectures. These are also great for use at school and university. Do you need a Universaldenker style physics video on a specific topic? Then you can order a physics video.
Video
Level 2 (suitable for students)

## Mass Sepctrometer Explained Simply in 7 Minutes

In this physics video, you will learn how a mass spectrometer is constructed and how you can use it to determine the mass of charged particles.

Content of the video
1. [00:00] Introduction
2. [00:25] Velocity selector (electric & magnetic force).
3. [03:20] Derive velocity of particle
4. [04:24] Derive mass formula
5. [06:25] Specific charge, neutrons and facts
Video
Level 1 (suitable for all)

## Voltage: The Most Basic Explanation From a Physics Point of View

Here you will learn what voltage is, how it is generated by charge separation, how a voltage source can be created, and what voltage has to do with current.

Content of the video
1. 00:00 Positive and negative electric charge
2. 01:12 Charge separation generates voltage
3. 02:58 Voltage is energy per charge
4. 05:33 Voltage source and electric current
5. 08:09 Is voltage dangerous?
Video
Level 2 (suitable for students)

## Ohm's Law: 2 Easy Ways to Understand and Apply It to Circuits

Here you will learn how to recognize Ohm's Law in a U-I diagram and how to apply the associated URI formula. Three examples are covered.

Content of the video
1. [00:00] Introduction
2. [00:33] The 1st ingredient: Voltage
3. [01:21] The 2nd ingredient: Electrical conductor
4. [01:48] The 3rd ingredient: Electric current
5. [03:18] Data points and Ohm's law as a graph
6. [05:49] Ohmic conductors
7. [06:41] Slope of the graph
8. [07:42] Ohm's law as a formula
9. [10:07] Example #1: Resistance unknown
10. [10:33] Example #2: Voltage unknown
11. [11:01] Example #3: Current unknown
Video

## Differential Equations explained simply in 47 minutes!

In this Lecture you will learn to classify and to solve arbitrary differential equations (ODE / PDE) in 42 minutes.

Content of the video
1. [00:16] Why do I need differential equations?
2. [00:47​] What is a differential equation?
3. [03:41​] Different notations of a differential equation
4. [05:19​] What should I do with a differential equation?
5. [06:31​] How to identify a differential equation
6. [07:28​] What are coupled differential equations?
7. [08:53​] Classification: Which DEQ types are there?
8. [16:05​] What are DEQ constraints?
9. [18:24] Difference between boundary and initial conditions
10. [20:55​] Solving method #1: Separation of variables
11. [21:08​] Example: Radioactive Decay law
12. [22:50​] Solving method #2: Variation of constants
13. [25:59​] Example: RL Circuit
14. [29:14​] Solving method #3: Exponential ansatz
15. [34:50​] Example: Oscillating Spring
16. [41:15​] Solving method #4: Product / Separation ansatz
Video

## Kronecker delta explained simply in 11 minutes!

In this video you will learn the Kronecker delta within 10 minutes and how you can use it to write down the scalar product in index notation.

Content of the video
1. [00:00] Hello there!
2. [00:42] Definition and Examples
3. [01:52] Einstein's Summation convention
4. [02:49] 4 Rules for Kronecker delta
5. [06:38] Scalar product with Kronecker delta
Video

## Schrodinger Equation explained extensively in 50 minutes!

In this quantum mechanics lecture you will learn the Schrödinger equation (1d and 3d, time-independent and time-dependent) within 45 minutes.

Content of the video
1. [00:10] What is a partial second-order DEQ?
2. [01:08] Classical Mechanics vs. Quantum Mechanics
3. [04:38] Applications
4. [05:24] Derivation of the time-independent Schrödinger equation (1d)
5. [17:24] Squared magnitude, probability and normalization
6. [25:37] Wave function in classically allowed and forbidden regions
7. [35:44] Time-independent Schrödinger equation (3d) and Hamilton operator
8. [38:29] Time-dependent Schrödinger equation (1d and 3d)
9. [41:29] Separation of variables and stationary states
Video
Level 1 (suitable for all)

## Electric Current explained simply in 7 minutes!

In this video you will learn the basics of the electric current, i.e. the definition, its physical meaning and unit.⠀

Content of the video
1. [00:00] Electric charges
2. [01:50] What causes the electric current?
3. [03:21] Formula + unit of electric current
4. [05:22] Is one ampere a large current?
5. [06:23] Summary
Video
Level 2 (suitable for students)

## Classical Double-Slit Experiment explained simply in 16 minutes!

In this video, Young's double-slit experiment with light is explained in a simple way. How the interference pattern of the double-slit is formed and which role light diffraction plays.

Content of the video
1. ⏲ [00:12] A bit of history
2. ⏲ [02:13] Setup + observation
3. ⏲ [03:43] Interference and wave path difference
4. ⏲ [05:26] Interference pattern explained
5. ⏲ [11:23] Derivation (formula for wavelength)
Video
Level 2 (suitable for students)

## Plate Capacitor explained simply in 7 minutes!

Here the plate capacitor is simply explained. With the help of the capacitor you will learn about the electric voltage, electric field and electric capacitance and how to calculate them for a plate capacitor.

Content of the video
1. ⏲ [00:11] Setup and Applications of a plate capacitor
2. ⏲ [01:58] Voltage
3. ⏲ [03:38] Capacitance
4. ⏲ [04:57] Force on a test charge & Electric field
Video

## Maxwells Equations explained extensively in 40 minutes!

The Maxwell’s equations are studied in the second semester of physics. Here you will learn EVERYTHING about them just within 40 minutes - explained for BEGINNERS!

Content of the video
1. ⏲ [00:14] Applications of the Maxwell equations
2. ⏲ [02:08] Electric field vector
3. ⏲ [05:12] Magnetic field vector
4. ⏲ [10:15] Divergence integral theorem - this mathematical theorem combines the volume integral of the divergence of a vector field with the surface integral of this vector field.
5. ⏲ [10:15] Divergence integral theorem - this mathematical theorem combines the volume integral of the divergence of a vector field with the surface integral of this vector field.
6. ⏲ [17:50] Curl integral theorem - this mathematical theorem combines the surface integral of the curl of a vector field with the line integral of this vector field.
7. ⏲ [23:58] The FIRST Maxwell’s equation - states that the charges are sources and sinks of the electric field.
8. ⏲ [27:46] The SECOND Maxwell’s equation - states that magnetic charges always occur as dipoles. There are no magnetic monopoles.
9. ⏲ [30:23] The THIRD Maxwell’ equation (Faraday’s law of induction) - states that a time-varying magnetic field generates an electric field and vice versa. This Maxwell equation contain also the Lenz’s rule.
10. ⏲ [35:02] THE FOURTH Maxwell’s equation - states that the magnetic field can be generated by electric currents and time-varying electric fields (displacement current)