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Grade 12Mechanics

Kindly explain me this question
  • Two conducting spherical conducting shells of radii r aand R ( r

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9 Years agoGrade 12
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ApprovedApproved Tutor Answer11 Months ago

To understand the behavior of two conducting spherical shells with radii \( r \) and \( R \) (where \( r < R \)), we need to delve into some fundamental concepts of electrostatics and how conductors interact with electric fields. Let's break this down step by step.

Basic Properties of Conductors

Conductors have unique properties when it comes to electric charge and fields. When a conductor is in electrostatic equilibrium, the electric field inside the conductor is zero. This means that any excess charge resides on the surface of the conductor. Additionally, the surface charge distribution can vary based on the external electric fields and the geometry of the conductor.

Interaction Between Two Spherical Shells

When we have two spherical conducting shells, the interaction between them can be analyzed based on their radii and the charges they carry. Let's consider the following scenarios:

  • Isolated Shells: If both shells are isolated and uncharged, there will be no electric field between them, and they will not influence each other.
  • Charged Inner Shell: If the inner shell (radius \( r \)) is charged with a charge \( Q \), it will induce a charge of \(-Q\) on the inner surface of the outer shell (radius \( R \)). The outer surface of the outer shell will then have a charge of \( +Q \) to maintain overall charge neutrality.
  • Charged Outer Shell: If the outer shell is charged while the inner shell remains neutral, the outer shell's charge will not affect the inner shell since the electric field inside a conductor is zero.

Electric Field Analysis

To analyze the electric fields in this system, we can use Gauss's Law, which states that the electric flux through a closed surface is proportional to the enclosed charge. Here’s how it applies:

  • For a Gaussian surface inside the inner shell (radius less than \( r \)), the electric field \( E \) is zero because there is no enclosed charge.
  • For a Gaussian surface between the two shells (radius between \( r \) and \( R \)), the electric field can be calculated using the charge \( Q \) on the inner shell. The electric field \( E \) at a distance \( d \) from the center (where \( r < d < R \)) is given by:

    E = \frac{1}{4\pi \epsilon_0} \cdot \frac{Q}{d^2}

  • For a Gaussian surface outside the outer shell (radius greater than \( R \)), the total charge enclosed is \( Q \) (from the inner shell) plus \( +Q \) (from the outer shell), leading to:

    E = \frac{1}{4\pi \epsilon_0} \cdot \frac{2Q}{d^2}

Practical Implications

This understanding of how charges distribute and how electric fields behave in the presence of conducting shells is crucial in various applications, such as capacitors, shielding sensitive electronic components, and understanding electrostatic forces in different configurations.

Conclusion

In summary, the interaction between two conducting spherical shells involves the distribution of charges and the resulting electric fields. The inner shell influences the outer shell through induced charges, while the outer shell's charge does not affect the inner shell due to the properties of conductors. This fundamental principle is key to grasping more complex electrostatic systems.