Gauss's Theorem (or Gauss's Law) is a fundamental law in electromagnetism. It states that the total electric flux through a closed surface is equal to the net charge enclosed divided by the permittivity of free space. It is incredibly useful for finding the electric field of symmetric charge distributions.
Gauss's law is most useful when the charge distribution has high symmetry (spherical, cylindrical, or planar).
The imaginary closed surface used for calculations is called a Gaussian surface.
The electric field inside any charged hollow conductor is always zero.
By imagining a cylindrical Gaussian surface around the wire, we can find the electric field at a distance 'r' from the wire.
By using a cylindrical 'pillbox' Gaussian surface that pierces the sheet, the electric field is found to be uniform, independent of distance from the sheet.
Yes, Gauss's law is technically always true for any closed surface. However, it is only practically useful for calculating the Electric Field (E) when high symmetry allows E to be pulled out of the integral.
A Labourer Moving a Loaded Cart — Work Done and Force Analysis
Work done by a labourer moving a loaded cart equals force × displacement × cosθ. If the force is perpendicular to displacement, work done is zero.
A Metallic Sphere Weighing 3 kg in Air — Find Density
A metallic sphere weighs 3 kg in air and 2.5 kg in water. Density = 6000 kg/m³ = 6 g/cm³. Step-by-step Archimedes principle solution.
An Electron Moves Along Vertical Line and Towards Observer — Magnetic Field Direction
When an electron moves towards the observer, the magnetic field is clockwise (viewed from front). Use the left-hand rule or reverse right-hand rule for electrons.
What is an Aneroid Barometer?
Learn about the aneroid barometer, an instrument used to measure atmospheric pressure without using liquid mercury. Perfect for geography and physics students.
Angle of Friction — Definition, Formula and Relation
Learn the definition of the angle of friction. Understand the formula tan θ = μ, relation with the coefficient of friction, and angle of repose.
Turn this guide into revision flashcards, a practice exam, or an AI-generated podcast — free, no signup required.