Gauss’ Law and Its Applications

IMPORTANT

Gauss’ Law and Its Applications: Overview

This topic covers concepts, such as, Gauss Theorem in Electrostatics, Electric Field inside the Overlapping Region of Two Oppositely Charged Spheres & Electric Field inside the Cylindrical Cavity of Uniformly Charged Cylinder etc.

Important Questions on Gauss’ Law and Its Applications

EASY
IMPORTANT

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:

HARD
IMPORTANT

Applying Gauss theorem, the expression for the electric field intensity at a point due to an infinitely long, thin, uniformly charged straight wire is

EASY
IMPORTANT

A hollow charged metal sphere has radius r. If the potential difference between its surface and a point at a distance 3r from the centre is V, then electric field intensity at a distance 3r is:

EASY
IMPORTANT

Assertion: Gauss's law can't be used to calculate electric field near an electric dipole.
Reason: Electric dipole don't have symmetrical charge distribution.

EASY
IMPORTANT

Let the electrostatic field, E at distance, r from a point charge, q not be an inverse square but instead an inverse cubic, e.g. E=kqr3r^, here k is a constant. Consider the following two statements: (I) Flux through a spherical surface enclosing the charge is, ϕ=qenclosedε0. (II) A charge placed inside a uniformly charged shell will experience a force. Which of the above statements are valid?

EASY
IMPORTANT

A point electric charge Q is placed at a corner of a cube as shown in the figure. What is the electric flux passing through ABCD of the cube? (0 is permittivity of free space)

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MEDIUM
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A point charge Q, is placed at the center of a cube of side a, in vacuum (permitivity ϵ0. The flux of the electric field through the shaded face is given by

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MEDIUM
IMPORTANT

A sphere of radius R carries a positive charge density (ρ) that increases linearly with radial distance r from the centre (ρr). The radial dependence of the magnitude of electric field inside the sphere is given by

EASY
IMPORTANT

A hollow cylinder has a charge q coulomb within it. If ϕ is the electric flux in units of Volt meter associated with the curved surface B, the flux linked with the plane surface A in units of Volt meter will be

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EASY
IMPORTANT

A parallel plate capacitor has two square plates with equal and opposite charges. The surface charge densities on the plates are +σ and σ respectively. In the region between the plates the magnitude of the electric field is

HARD
IMPORTANT

The potential (in volts) of a charge distribution is given by

Vz=30-5z2 for z1 m

Vz=35-10 z for Z1 m .

V(z) does not depend on x and y. If this potential is generated by a constant charge per unit volume ρ0 (in units of ϵ0 ) which is spread over a certain region, then choose the correct statement.

EASY
IMPORTANT

The ratio of electric field intensity at P & Q in the shown arrangement is


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EASY
IMPORTANT

A charge Q is placed at a distance a2 above the centre of a square surface of side length a. The electric flux through the square surface due to the charge would be?
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HARD
IMPORTANT

Consider a uniformly charged solid cylinder of large length and radius R. Now consider a cylindrical surface of radius 2R and length 2R coaxial with cylinder and electric flux through cylindrical surface is ϕ0. Now consider a spherical surface of radius 2R and one of the diameter along axis of cylinder and electric flux through spherical surface is ϕ. Find 10ϕϕ0 to the nearest integer.

EASY
IMPORTANT

In the shown figure a hemisphere is placed and two charges 3q and 9q are placed symmetrically about centre O. Net electric flux over curved surface is given as N1qN2ε0, where N1 and N2 are lowest possible integers then value of N1+N2 is :

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HARD
IMPORTANT

The electric field in a region is radially outwards with magnitude E=αrϵ0. In a sphere of radius R centered at the origin, calculate the value of charge in coulombs if α=5πV/m2 and R=3101/3 m

HARD
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 KR22Nε0 Then N will be.

EASY
IMPORTANT

A point charge of +12 μC is at a distance 6 cm vertically above the centre of a square of side 12 cm as shown in figure. The magnitude of the electric flux through the square will be _________ ×103 N m2 C-1.(Write the value to the nearest integer)

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HARD
IMPORTANT

A circular disc of radius R carries surface charge density σr=σ01-rR, where σ0 is a constant and r is the distance from the center of the disc. Electric flux through a large spherical surface that encloses the charged disc completely is ϕ0Electric flux through another spherical surface of radius R4 and concentric with the disc is ϕ. The ratio ϕ0ϕ=x5, find the value of x.

HARD
IMPORTANT

In the figure shown, there is a large sheet of charge of uniform surface charge density σ. A charge particle of charge -q and mass m is projected from a point A on the sheet with a speed u with angle of projection such that it lands at maximum distance from A on the sheet. Neglecting gravity, find the time of flight.

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