Two coils of wire are placed close together. Initially, a current of 1.80 A exists in one of the coils, but there is no current in the other. The current is then switched off in a time of 4.02 x 10-2 s. During this time, the average emf induced in the other coil is 4.38 V. What is the mutual inductance of the two-coil system?

the mutual inductance is - 0.0978H

Explanation:

Detailed explanation and calculation is shown in the image below

truck y has a greater velocity than truck x.

96.77 amp

explanation:

rl = 250/100 = 2.5 ohms.

egl = 250 + (100 × 0.1) + 2 = 262 v.

at 700 r.p.m., eg2 = 262 × 700/1000 = 183.4 v.

if ia is the new current, then eg2 - 2 - (ia × 0.1) = 2.5 ia

which means this will give ia = 96.77 amp.