Gauss' Law

IMPORTANT

Gauss' Law: Overview

This topic covers concepts such as Gauss Theorem in Electrostatics, Condition for the Validity of Gauss Theorem, Important Points in Gauss's Law, Proof of Coulomb's Law Using Gauss Law, and Proof of Gauss Law.

Important Questions on Gauss' Law

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Which law is used to derive the expression for the electric field between two uniformly charged large parallel sheets with surface charge densities σ and σ respectively:

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A closed spherical surface encloses a charge q at its centre. Show that the electric flux through the closed surface is qε0.

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The inward and outward electric flux from a closed surface are respectively 8×103 and 4×103 units. Then the net charge inside the close surface is

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An electric field E is present r to a square plate of side length L. What is the flux passing through the plate?

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A charge Q is distributed uniformly in a sphere (solid). Then the electric field at any point r, where r<R ( r is radius of sphere) varies as_____.

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Two infinitely long parallel conducting plates having surface charge densities +σ and -σ respectively are separated by a small distance. The medium between the plates is vacuum, if εo is dielectric permittivity of vacuum, then the electric field in the region between the plates is-

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A sphere of radius R have volume charge density given as
ρ(r)=Kr for rR

=0 for r>R
If electric field at distance R2 from centre is KR22Nε0 Then N will be.

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The total flux through the faces of the cube with side of length α if a charge q is placed at corner A of the cube is
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A point charge of 1.8 μC is at the centre of cubical Gaussian surface 55 cm on edge. What is the net electric flux through the surface?

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A ring of radius R having a linear charge density λ moves towards a solid imaginary sphere of radius R2, so that the centre of ring passes through the centre of the sphere. The axis of the ring is perpendicular to the line joining the centres of the ring and the sphere. The maximum flux through the sphere in this process is

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Flux coming out from a unit positive charge enclosed in air is

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A Gaussian sphere encloses an electric dipole within it. The total flux across the sphere is

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q1, q2, q3 and q4 are point charges located at points, as shown in the figure, and S is a spherical Gaussian surface of radius R. Which of the following is true, according to the Gauss' law?

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The figure shows a closed surface which intersects a conducting sphere. If a positive charge is placed at the point P, the flux of the electric field through the closed surface, 

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A Gaussian sphere encloses an electric dipole within it. The total flux through the sphere is

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Flux coming out from a unit positive charge enclosed in air is

MEDIUM
IMPORTANT

A sphere of radius R have volume charge density given as
ρ(r)=Kr for rR

=0 for r>R
If electric field at distance R2 from centre is KR2Nε0 Then N will be.

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IMPORTANT

An uncharged thick spherical conducting shell is surrounding a charge -q at the centre of the shell. Then charge +3q is placed on a point outside the shell. When static equilibrium is reached, the total charges on the inner and outer surfaces of the shell are respectively

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The charge density inside a nucleus is given by ρ=ρ01-r2a2 where ra,a=radius of nucleus =3 fm and ρ0=5×1025 C m-3. The electric field is maximum at r=r0. If r0=5xa, find the value of x.

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State Gauss' theorem in electrostatics and write its expression.