A 310 turn solenoid with a length of 22.0 cm and a radius of 1.70 cm carries a current of 2.10 A. A second coil of four turns is wrapped tightly around this solenoid, so it can be considered to have the same radius as the solenoid. The current in the 310 turn solenoid increases steadily to 5.00 A in 0.900 s.
(a) Use Ampere's law to find out the initial magnetic field in the middle of the 310 turn solenoid.
(b) find out the magnetic field of the 310 turn solenoid after 0.900 s.
(c) find out the area of the 4-turn coil.
(d) find out the change in the magnetic flux through the 4-turn coil during the same period.
(e) find out the average induced emf in the 4-turn coil. Is it equal to the instantaneous induced emf? describe.
(f) Why could contributions to the magnetic field by the current in the 4-turn coil be neglected in this calculation?