In a pure inductive circuit, the phase difference between voltage and current is: 0 degrees 30 degrees 60 degrees 90 degrees

Time t < 0, the circuit is in DC Steady State.  The switch is opened instantly at time t=0.  This question deals with the new initial conditions for t>0.  When t<0, I₂ = 7 A, and I₃ = 9 A. Give I₂ at t=0+ (at t=0, but after the switch is opened).

A solenoid with 485 turns has a length of 5.50 cm and a cross-sectional area of 3.20 ✕ 10−9 m2. Find the solenoid's inductance and the average emf around the solenoid if the current changes from +3.50 A to −3.50 A in 5.33 ✕ 10−3 s (a) the solenoid's inductance (in H) ____ H (b) the average emf around the solenoid (in V)  ____V

Do it correctly!