Questions from Electronics

Q: Three point charges are located as shown in Fig. 3.

Three point charges are located as shown in Fig. 3.38, each a distance a from the origin. Find the approximate electric field at points far from the origin. Express your answer in spher...

Q: A solid sphere, radius R, is centered at the origin

A solid sphere, radius R, is centered at the origin. The “northern” hemisphere carries a uniform charge density ρ0, and the “southern” hemisphere a uniform charge density −ρ0. Find the approximate fiel...

Q: Show that the electric field of a (perfect) dipole (

Show that the electric field of a (perfect) dipole (Eq. 3.103) can be written in the coordinate-free form

Q: In Section 3.1.4, I proved that the

In Section 3.1.4, I proved that the electrostatic potential at any point P in a charge-free region is equal to its average value over any spherical surface (radius R) centered at P. Here’s an alternat...

Q: Here’s an alternative derivation of Eq. 3.10 (the

Here’s an alternative derivation of Eq. 3.10 (the surface charge density induced on a grounded conducted plane by a point charge q a distance d above the plane). This approach19 (which generalizes to...

Q: Two infinite parallel grounded conducting planes are held a distance a apart

Two infinite parallel grounded conducting planes are held a distance a apart. A point charge q is placed in the region between them, a distance x from one plate. Find the force on q.20 Check that your...

Q: (a) Show that the average electric field over a spherical

(a) Show that the average electric field over a spherical surface, due to charges outside the sphere, is the same as the field at the center. (b) What is the average due to charges inside the sphere?

Q: Sketch the vector function / and compute its divergence.

Sketch the vector function and compute its divergence. The answer may surprise you. . . can you explain it?

Q: Two long straight wires, carrying opposite uniform line charges λ,

Two long straight wires, carrying opposite uniform line charges λ, are situated on either side of a long conducting cylinder (Fig. 3.39). The cylinder (which carries no net charge) has ra...

Q: Buckminsterfullerine is a molecule of 60 carbon atoms arranged like the stitching

Buckminsterfullerine is a molecule of 60 carbon atoms arranged like the stitching on a soccer-ball. It may be approximated as a conducting spherical shell of radius R=3.5 Å. A nearby electron would be...