Two closely wound coaxial solenoids form a primary–secondary pair with a mutual inductance of 0.20H. The current in the primary is increased uniformly from 0 to 4.0A in 10ms.
(a) Calculate the average magnitude of the emf induced in the secondary during this interval.
(b) The secondary is a closed circuit of resistance 5.0Ω. Find the total charge that flows through the secondary in this time.