$1.$ What is the difference between the magnetic flux and magnetic field?

$2.$ Discuss the similarities between the energy stored in the electric field of a charged

capacitor and the energy stored in the magnetic field of a current$-$carrying coil.

$3.$ A piece of aluminum is dropped vertically downward between the poles of an electro$-$

magnet. Does the magnetic field affect the velocity of the aluminum? Explain your

answer.

$4.$ We have discussed that a static magnetic field cannot change the energy of a charged

particle $($it can$$t do any work$).$ Is the same true of a changing magnetic field? Explain.

$5.$ Describe two practical devices that rely on Faraday$$s law to work.

$6.$ If you wind a solenoid around an iron core $($the iron is there to beef up the magnetic

field$),$ place a metal ring on top, and plug it in$,$ the ring will jump several feet in the

air. Why?

$7.$ What is meant by the curl of a vector. Explain why, if the curl of a vector is zero,

then that vector can be written as the gradient of a scalar.

$8.$ Explain why the divergence of the curl of a vector is always zero.

$9.$ What is $$ ~J$?$ Note: Your answer is only true for a time$-$independent charge density,

$,$ and not true in general. We will come to the correct answer later.