Describe the electric field inside a charged spherical shell.

The electric field inside a charged spherical shell is zero.

In more detail, this is a fundamental concept in electrostatics, derived from Gauss's law. Gauss's law states that the electric flux through a closed surface is proportional to the charge enclosed by that surface. If we consider a Gaussian surface inside the spherical shell, since there is no charge enclosed by this surface, the electric field must be zero.

The spherical shell is assumed to be uniformly charged. This means that the charge is distributed evenly over the surface of the shell. The electric field is a vector quantity, and at every point inside the shell, there are equal and opposite contributions to the electric field from opposite parts of the shell. These contributions cancel each other out, resulting in a net electric field of zero.

It's important to note that this result holds true regardless of the position inside the shell. Whether you are at the centre of the shell or near the inner surface, the electric field is still zero. This is because the electric field depends only on the charge enclosed by the Gaussian surface, not on its shape or size. As long as the Gaussian surface is inside the shell and does not enclose any charge, the electric field will be zero.

This concept has significant implications in physics and engineering. For example, it explains why the electric field inside a metal object is zero when the object is in electrostatic equilibrium. The free electrons in the metal will rearrange themselves on the surface of the object until the electric field inside is zero. This is why you are safe inside a car during a lightning storm. The car acts like a charged spherical shell, and the electric field inside is zero, so the lightning does not affect you.

In summary, the electric field inside a charged spherical shell is zero, due to the symmetry of the shell and the principles of Gauss's law. This is a key concept in electrostatics with wide-ranging applications.