One solenoid is centered inside another. The outer one has a length of 50 centimeter and contains 6800 coils, while the coaxial inner solenoid is 5 centimeter long and 0.180 centimeter in diameter and contains 20 coils. The current in the outer solenoid is changing at 35.5 A/s.
Estimate the mutual inductance of these solenoids?
Estimate the emf induced in the inner solenoid.