Alexander Fufaev

Physics videos

Here you will find 9 free physics videos. These are suitable for use in school and university.

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

Ohm's law explained simply in 13 minutes!

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] Hello there!
  2. [00:44] The 1st ingredient: Voltage
  3. [01:30] The 2nd ingredient: Electrical conductor
  4. [01:57] The 3rd ingredient: Electric current
  5. [03:28] Data points and Ohm's law as a graph
  6. [05:58] Ohmic conductors
  7. [06:44] Slope of the graph
  8. [07:52] Ohm's law as a formula
  9. [10:10] Electrical resistance
  10. [10:16] Example #1: Resistance unknown
  11. [10:42] Example #2: Voltage unknown
  12. [11:10] Example #3: Current unknown
Video

Voltage explained simply in 10 minutes!

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​] Hello there!
  2. [00:48​] Positive and negative electric charge
  3. [02:00​] Charge separation generates voltage
  4. [03:46​] Voltage is energy per charge
  5. [06:21​] Voltage source and electric current
  6. [08:57] Is voltage dangerous?
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

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. ⏲ [00:25] Electric charges
  2. ⏲ [02:11] What causes the electric current?
  3. ⏲ [03:42] Formula + unit of electric current
  4. ⏲ [05:43] Is one ampere a large current?
  5. ⏲ [06:44] Summary
Video

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

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)