Ex29 Two solenoids of the same length L and number of turns N are arranged one inside the other coaxially. The largest, of section S1, carries a current I(t) = a t where a is a constant. Calculate the expression for the voltage induced across the small solenoid, of section S2. We then supply the small one with the same current and we measure the voltage induced across the big one; calculate the ratio of the two voltages. Answer: -μoN2S2 α /L, 1

Ex29 Two solenoids of the same length L and number of turns N are arranged one inside the other coaxially. The largest, of section S1, carries a current I(t) = a t where a is a constant. Calculate the expression for the voltage induced across the small solenoid, of section S2. We then supply the small one with the same current and we measure the voltage induced across the big one; calculate the ratio of the two voltages. Answer: -μoN2S2 α /L, 1