The current in a solenoid increases at a constant rate from zero to 10 amps in one second. the cross-sectional area of the solenoid is .000315m^2, and there are 300 turns of conducting wire over its 0.15m length.
What is the magnetic field in the center of the solenoid at 0.5 seconds?
What is the inductance of the solenoid?
What is the back emf during the first second?