One application of an RL circuit is the generation of time varying high-voltage from a low-voltage source as shown in the figure.(adsbygoogle = window.adsbygoogle || []).push({});

1257 ohms

14 ohms 2 H (switch) b

a

12.6 V.

Sorry, I couldn't get the picture, but heres a rough idea.. it's in a circuit.

What is the current in the circuit a long time after the switch has been in position "a"?

I got this part... it was0.9 A

Part 2 says: Now the switch is thrown quickly from "a" to "b". Compute the initial voltage across the inductor.

I got this too.. it was1143.9 V

Part 3 says: How much time elapses before the voltage across the inductor drops to 13 V? Answer in units of ms.

I used the equation [tex] I= I_0 e^ (-R/L)t [/tex]

and then figured out that [tex] V= I_0 Re^(-R/L)t [/tex]

so 13.0 V=(0.9)(1143.9)e^(1143.9t/2)

solving for t gave me 7.64 ms which isnt' right.. can someone please help me?

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# RL circuit Voltage problem

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