Question

There are a lot of numbers in this problem. Just about the only way to get it right is to work out each step symbolically first, and then plug numbers into the final symbolic result. 

Two coils of wire are aligned with their axes along the z-axis, as shown in the diagram. Coil 1 is connected to a power supply and conventional current flows clockwise through coil 1, as seen from the location of coil 2. Coil 2 is connected to a voltmeter. The distance between the centers of the coils is 0.17 m. 

Coil 1 has N1 = 560 turns of wire, and its radius is R1 = 0.09 m. The current through coil 1 is changing with time. At t=0 s, the current through coil 1 is I0 = 16 A. At t=0.4 s, the current through coil 1 is I0.4 = 6 A. 

Coil 2 has N2 = 235 turns of wire, and its radius is R2 = 0.04 m.

Inside coil 2, what is the direction of −dvectorbcap.gif/dt during this interval?

What is the direction of the electric field inside the wire of coil 2, at a location on the top of coil 2? 

At time t=0, what is the magnetic flux through one turn of coil 2? Remember that all turns of coil 1 contribute to the magnetic field. Note also that the coils are not very far apart (compared to their radii), so you can't use an approximate formula here.

Answer 1