A wide solenoid with 7500 turns of wire is 50 cm long with its main axis aligned along the vertical direction. The current in the solenoid is initially 2 A and is circling counter-clockwise as viewed from above.
a) What is the magnetic field, both magnitude and direction inside the solenoid?
b) The magnetic field strength inside the solenoid increases to 2.5T in 2.0 seconds. What is the new current in the solenoid?
c) Inside the larger solenoid is a smaller coil with 40 turns, radius 2.0 cm, and resistance of 20 ohms. Find the magnitide and direction of the induced current in the smaller coil caused by the changing flux.