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pronep

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## Homework Statement

If You want to turn on the current through a coil of self inductance L in a controlled manner, so you place it in series with a resistor R= 2200 ohm, a switch, and a dc voltage source Vo=240 V. After closing the switch, you find that the current through the coil builds up to its steady=state value with a time constant T. You are pleased with the current's steady-state, but want T to be half as long. What new values should you use for Rand Vo.?## Homework Equations

T=L/R

I= Vo/R (1-e^(-t/T))

## The Attempt at a Solution

I= 240/2200(1-e^(-t/T))

I'= Vo'/R'(1-e^(-2t/T))

Since, I=I'

240/2200(1-e^(-t/T))=Vo'/R'(1-e^(-2t/T)

Can somebody point out what I am missing here? Thanks