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Grade 9General Physics

What happens if we give a single electron charge to a hollow metal sphere?

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12 Years agoGrade 9
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ApprovedApproved Tutor Answer0 Years ago

When we give a single electron charge to a hollow metal sphere, several interesting phenomena occur due to the properties of conductors and electrostatics. Let’s break this down step by step to understand what happens.

The Basics of Charge Distribution

First, it’s important to recognize that a metal sphere is a conductor. Conductors allow charges to move freely throughout their surface. When we add a single electron to the hollow metal sphere, this charge will not remain at the point of application. Instead, it will redistribute itself across the entire surface of the sphere.

Why Does Charge Distribute?

The reason for this redistribution lies in the principle of electrostatics: like charges repel each other. When the electron is added, it experiences repulsive forces from other electrons on the surface of the sphere. To minimize these repulsive forces, the electrons spread out as far as possible, resulting in a uniform distribution of charge over the surface of the sphere.

Effects on the Electric Field

Now, let’s consider the electric field generated by this charged sphere. Inside the hollow part of the sphere, the electric field is zero. This is a fascinating property of conductors: any excess charge resides on the outer surface, and the electric field inside a conductor in electrostatic equilibrium is always zero. This means that if you were to place a test charge inside the hollow sphere, it would not experience any force due to the electric field.

Electric Field Outside the Sphere

Outside the sphere, however, the situation is different. The electric field behaves as if all the charge were concentrated at the center of the sphere. For a sphere with a total charge of +1 electron (which is approximately -1.6 x 10-19 coulombs), the electric field at a distance r from the center of the sphere can be calculated using Coulomb's law:

  • The formula for the electric field (E) at a distance r from a point charge (Q) is given by: E = k * |Q| / r2,
  • where k is Coulomb's constant (approximately 8.99 x 109 N m2/C2).

So, if you were to measure the electric field at a point outside the sphere, you would find it to be directed radially outward from the center of the sphere, decreasing in strength with the square of the distance from the center.

Implications of the Charge

Adding a single electron charge to the hollow metal sphere also has implications for its potential. The potential (V) at the surface of the sphere can be calculated using the formula:

  • V = k * Q / R,

where R is the radius of the sphere. This potential is constant across the surface of the sphere due to the uniform distribution of charge.

Summary of Key Points

  • The charge redistributes uniformly across the surface of the hollow metal sphere.
  • The electric field inside the sphere is zero, while outside it behaves as if all the charge were concentrated at the center.
  • The potential is constant across the surface of the sphere.

In essence, charging a hollow metal sphere with a single electron leads to a fascinating interplay of electrostatic principles, showcasing the unique behavior of conductors and electric fields. This understanding is crucial in fields ranging from electrostatics to electrical engineering.