Coil A is a large 300 turn circular coil of radius 77 cm. Circular coil B has 390 turns, a radius of 5 cm and is located L=99 cm from coil A along the same axis. The planes of the two coils are parallel. A) Find the approximate mutual inductance of this pair of coils.     for my answer I got 3.527E-10 H which was wrong B) If the current in coil A varies with time according to I=3t3−8t2−1, where I is in amps and t is in s, find the magnitude of the EMF induced in coil B at time t=2 s.

A toroidal solenoid has 550 turns, cross-sectional area 6.40 cm^2, and mean radius 4.60 cm. Part A Calcualte the coil's self-inductance. Part B If the current decreases uniformly from 5.00 AA to 2.00 AA in 3.00 msms, calculate the self-induced emf in the coil.

Lenz's Law: The induced EMF will fight the change in current through an -Ld where Lis called the "inductance". The MKS units dt inductor: € - for inductance are Henry's (H). Note that L is greater than zero by definition. The minus sign tells you which direction the induced current will point. A) An induced emf of 20 mV is measured across a coil of 50 closely wound turns while the current through it increases uniformly from 0.0 to 5.0 A in 0.10 s. What is the self-inductance of the coil? Answer: L = 4.0x10-4 H B) The magnetic flux in a solenoid is related to the self- inductance L of the solenoid via the following: m = LI/N where m is the magnetic flux through one loop and N is the number of loops. N² A Show that the inductance for a solenoid is solenoid = μo Но where A is the area of the solenoid and I is the length of the solenoid.

Can ypu please help me with this question? Thank you so much!