1. The problem statement, all variables and given/known data Your circuit has a resistance of 175Ω and an ideal battery with an emf of 6.3V. What value of inductor should you add to the circuit to ensure the current increase in the first 58μs is less than 4.9mA? 2. Relevant equations I think E=L(di/dt) 3. The attempt at a solution E=L(di/dt) 6.3=L(4.9*10^-3/58*10^-6) L = 0.07457H But the answer is 0.069H Thanks.