Electricity and Magnetism Answers

Explain, in detail, the physics behind why the magnet slows its descent through the tube (it does not touch the sides). In your discussion be sure to explain why the magnet doesn't come to a stop in the tube and why it does not speed up. Your response should include at least 3 paragraphs to show your mastery of the material.

The electric field between the plates of charged parallel plate capacitor decreases from 12V/m to X V/m. If the number of atoms per unit volume is N x 1028 atoms m-3, the electronic polarisability of the material is
X = 6.00 N = 13.84

A circular current loop of radius 6 angstrom and a current of I pico Ampere is placed in a magnetic field of strength B T. find the potential energy of the magnetic dipole.
I = 69.20 B = 13.40

"An iron rod of length 0.5m has a cross sectional area of A x 10-4 m2. If the flux of magnetic induction through the bar is B x 10-4 Weber and relative permeability of iron is 1000, calculate, Magnetisation M and Intensity of magnetising field H
"
A = 1.96 B = 10.05

If two like charges, each having a charge of four micro coulombs sit .6meters apart. The force between them will be?

A vertical steel rod is 3 m long and has a radius of 0.1m. It is
supporting a load of 1 × 105 N. What is the stress in the rod?

A 2D annulus (thick ring) has an inner radius Ri and outer radius Ro, and charge Q non-uniformly distributed over its surface. The 2D charge density varies with radius r by n(r)=Cr^3 for Ri<= r<=Ro and n=0 for all other r. C is a constant. Answer the following in terms of the variables given above. 1-Find an expression for C such that the total charge of the annulus is Q. Include the SI units for C next to your answer.
Draw a clear picture and use it to set-up the integral to calculate the E-field at a point on the axis of the annulus (this axis is perpendicular to the plane of the annulus) a distance z from the center of the annulus. You must complete all the steps short of actually computing the integral( your final answer must be an integral with only one variable of integration and all other variables constant.) Show that your answer has the correct SI units for the electric field.

The airgap in a magnetic circuit is 1.1 mm long and 2000 mm2 in cross-section. Calculate: (i) the reluctance of the airgap; and (ii) the m.m.f. to send a f lux of 700 microwebers across the airgap.

A 50 loop circular coil has a radius of 3cm .it is oriented so that the field lines of a magnetic field are normal to the area of the coil .if the magnetic field is varied so that vector B increase from 0.10T to 0.35T in 2milliseconds,what is the average induced emf in the coil?

A coil of wire 8cm in diameter has 50turns and is placed in a B field of 1.8T. If the B field is reduced to 0.6T in 0.002seconds,what is the induced emf