Faraday's Law

Any change in the magnetic environment of a coil of wire will cause a voltage (emf) to be "induced" in the coil. No matter how the change is produced, the voltage will be generated. The change could be produced by changing the magnetic field strength, moving a magnet toward or away from the coil, moving the coil into or out of the magnetic field, rotating the coil relative to the magnet, etc.

Further comments on these examples

Faraday's law is a fundamental relationship which comes from Maxwell's equations. It serves as a succinct summary of the ways a voltage (or emf) may be generated by a changing magnetic environment. The induced emf in a coil is equal to the negative of the rate of change of magnetic flux times the number of turns in the coil. It involves the interaction of charge with magnetic field.

Introduction to Faraday's Law

Introduction to Faraday's Law

Question Details

A cylindrical iron rod of infinite length with cross-sectional area  is oriented with its axis of symmetry coincident with the z axis of a cylindrical coordinate system as shown in the figure. It has a magnetic field inside that varies according to . Find the theta component of the electric field at distance  from the z axis, where  is larger than the radius of the rod. (Shown in the figure)

 

 

I have the answer...    =

 

My professor did this in class and said that *hint* we should be familiar with this for an exam we have tomorrow. He worked through it very quickly, too quickly to hardly write down anything.

 

I just need to know the steps to get to the answer

 

any help would be much appreciated!