Chapter 13, Problem 68AP

A 2-turn planer loop of flexible wire is placed inside a long solenoid of n turns per meter that canes a constant current $I_0$ The area A of tire loop is changed by pulling

on its sides while ensuring that tire plane of the loop always remains perpendicular to tire axis of the solenoid. If n = 500 turns per meter, $I_0=20A$, and $A=20c{m}^2$ , what is the emf induced in the loop when $dA/dt=100$ ?