Final answer:
The mutual inductance between two magnetically coupled coils, given a change in flux and current reversal, is calculated using Faraday's law of induction. Solving with the provided figures yields a mutual inductance of 1.33 mH.
Step-by-step explanation:
The question provided concerns the calculation of mutual inductance between two coils based on given parameters and Faraday's law of induction. A change of magnetic flux (ΔΦ = 8mWb) in coil B results from a change in current (reversal of 3 A) in coil A. The self-inductance of coil A (LA) is 0.30 H, and coil B (LB) is 0.20 H, with coil A having 300 turns and coil B having 120 turns.
By applying Faraday's law of induction and the definition of mutual inductance (M = ΔΦ / ΔI), we can calculate M for coils A and B. Remember that the mutual inductance is a measure of how much a change in current in one coil induces a voltage in another coil, and it involves both the physical arrangement of the coils and the number of turns in each coil.
To solve for M, the change in current (ΔI) should be the total change, which for a reversal is double the original current. Since current is reversed from 3A to -3A, ΔI is 6A. Hence, M = ΔΦ / ΔI = 8 x 10-3 Wb / 6 A = 1.33 x 10-3 H or 1.33 mH.