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Grade 11Magnetism

A ring of radius R has charge Q uniformly distributed over its surface , with centre of ring as the centre of a sphere a sphere of radius R is contructed over the circumference of the ring .Find the flux through the surface of the sphere.....
please help and give the full solution with explanation of this question......

Profile image of Radhika Batra
12 Years agoGrade 11
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Profile image of Askiitians Tutor Team
ApprovedApproved Tutor Answer1 Year ago

To determine the electric flux through the surface of a sphere that is centered on a charged ring, we can apply Gauss's Law, which relates the electric flux through a closed surface to the charge enclosed by that surface. Let's break down the problem step by step.

Understanding the Setup

We have a ring of radius R that carries a total charge Q uniformly distributed over its surface. This ring is positioned such that its center coincides with the center of a sphere that has the same radius R. The sphere is constructed such that it encompasses the entire circumference of the ring.

Applying Gauss's Law

Gauss's Law states that the electric flux (Φ) through a closed surface is equal to the charge (Q_enc) enclosed by that surface divided by the permittivity of free space (ε₀):

Φ = Q_enc / ε₀

Identifying the Enclosed Charge

In this scenario, we need to determine the charge enclosed by the sphere. Since the sphere is centered on the ring and has a radius equal to that of the ring, it does not enclose any charge. The charge Q is distributed along the ring, which lies on the surface of the sphere but is not enclosed by it.

Calculating the Electric Flux

Since the sphere does not enclose any charge, we can conclude that:

Q_enc = 0

Substituting this into Gauss's Law gives us:

Φ = 0 / ε₀ = 0

Conclusion

The electric flux through the surface of the sphere is zero. This result can be understood intuitively: the electric field produced by the charged ring does not penetrate the sphere in a way that would contribute to a net flux through its surface, as the field lines from the ring extend outward and do not converge within the sphere.

Visualizing the Concept

Imagine the ring as a circular path of charge. The electric field lines radiate outward from the ring, but since the sphere is centered on the ring and does not enclose any charge, the contributions to the electric field at any point on the sphere's surface from opposite sides of the ring will cancel each other out. Thus, the net electric flux through the sphere remains zero.

This example illustrates the power of Gauss's Law in simplifying the analysis of electric fields and flux in symmetrical charge distributions. If you have any further questions or need clarification on any part of this explanation, feel free to ask!