- #1
Punchlinegirl
- 224
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One application of an RL circuit is the generation of time varying high-voltage from a low-voltage source as shown in the figure.
1257 ohms
14 ohms 2 H (switch) b
a
12.6 V.
Sorry, I couldn't get the picture, but here's 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 was 0.9 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 was 1143.9 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?
1257 ohms
14 ohms 2 H (switch) b
a
12.6 V.
Sorry, I couldn't get the picture, but here's 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 was 0.9 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 was 1143.9 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?