Hi! could anyone help me with this question please, I really don't know how to do this at all. Thank you so much.

Question

Question:A 330 turn solenoid with a length of 21.0 cm and a radius of 1.40 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 330 turn solenoid increases steadily to 5.00 A in 0.900 s.
(a) Use Ampere's law to calculate the initial magnetic field in the middle of the 330 turn solenoid.
___ T

(b) Calculate the magnetic field of the 330 turn solenoid after 0.900 s.
___ T

(c) Calculate the area of the 4-turn coil.
___ m2

(d) Calculate the change in the magnetic flux through the 4-turn coil during the same period.
____ Wb

(e) Calculate the average induced emf in the 4-turn coil.
____ V

Answer 1

http://teacher.pas.rochester.edu/phy122/Lecture_Notes/Chapter31/chapter31.html#Heading4

On e) use for dI/dt=5/.9 amps/sec