Questions from Electronics


Q: (a) Suppose the potential is a constant V0 over the

(a) Suppose the potential is a constant V0 over the surface of the sphere. Use the results of Ex. 3.6 and Ex. 3.7 to find the potential inside and outside the sphere. (Of course, you know the answers i...

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Q: The potential at the surface of a sphere (radius R)

The potential at the surface of a sphere (radius R) is given by V0 = k cos 3θ, where k is a constant. Find the potential inside and outside the sphere, as well as the surface charge density σ(θ) on th...

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Q: In one sentence, justify Earnshaw’s Theorem: A charged particle cannot

In one sentence, justify Earnshaw’s Theorem: A charged particle cannot be held in a stable equilibrium by electrostatic forces alone. As an example, consider the cubical arrangement...

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Q: Suppose the potential V0(θ) at the surface of a

Suppose the potential V0(θ) at the surface of a sphere is specified, and there is no charge inside or outside the sphere. Show that the charge density on the sphere is given by / where /

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Q: Find the potential outside a charged metal sphere (charge Q,

Find the potential outside a charged metal sphere (charge Q, radius R) placed in an otherwise uniform electric field E0. Explain clearly where you are setting the zero of potential.

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Q: Suppose that f is a function of two variables (y and

Suppose that f is a function of two variables (y and z) only. Show that the gradient / transforms as a vector under rotations, Eq. 1.29. and the analogous formula for /. We know that / And / &...

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Q: In Prob. 2.25, you found the potential on

In Prob. 2.25, you found the potential on the axis of a uniformly charged disk: / (a) Use this, together with the fact that Pl (1) 1, to evaluate the first three terms in the expansion (Eq. 3.72) for...

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Q: A spherical shell of radius R carries a uniform surface charge σ0

A spherical shell of radius R carries a uniform surface charge σ0 on the “northern” hemisphere and a uniform surface charge σ0 on the “southern” hemisphere. Find the potential inside and outside the s...

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Q: Solve Laplace’s equation by separation of variables in cylindrical coordinates, assuming

Solve Laplace’s equation by separation of variables in cylindrical coordinates, assuming there is no dependence on z (cylindrical symmetry). [Make sure you find all solutions to the radial equation; in...

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Q: Find the potential outside an infinitely long metal pipe, of radius

Find the potential outside an infinitely long metal pipe, of radius R, placed at right angles to an otherwise uniform electric field E0. Find the surface charge induced on the pipe. [Use your result fro...

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