- #1

- 62

- 0

## Homework Statement

so theres two solenoids on the same axis of symmetry, and the smaller one inside the larger one has a resistance of 11 ohms, 1000 turns, and radius .02 meters. the outer solenoid has n 18000 turns per meter, and had a current that is increasing at a constant rate with dI/dt=.7 Amps/sec. The inner solenoid is connected to an ammeter.

## The Attempt at a Solution

how would you find the induced current in the inner solenoid? i have an equation i tried using:

I

_{ind}=[(μ

_{0})(n(turns per meter))(I

_{max})(A)]/[(R)(Δt)]

made μ

_{0}=4pi(10

^{-7}), A=pi(0.02

^{2}) R=11, and since dI/dt=0.7 A/s i just made change in time equal 1 sec and I

_{max}equal 0.7 Amps. One thing I think that may be messed up is the value for n, in the problem were given how many exact turns it has which is N, and no length of the solenoid(s). But the equation i have uses n which is turns per meter. So i just put for n (18000).

Got 1.91(10

^{-6}) amps, but the correct answer is 1.81(10

^{-3}) amps...tried a few other things and im just kind of lost. Can somebody help me understand this?

Last edited: