Imagine two solenoids, both 10 cm long, one inside the other. The inner solenoid is 100 turns of wire wrapped around a circular cylindrical iron core (µ = 750xµ0) with a diameter of 1.5 cm. The second solenoid is 200 circular loops of wire with a diameter of 6.0 cm encircling the smaller solenoid. The current in the inner solenoid is turned on so that it goes from 0 to 500 mA in two seconds. What is the voltage generated in the outer solenoid?