Inductive time constant, value of resistance

Thread starter clockworks204
Start date Jul 9, 2010
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Constant Resistance Time Time constant Value

AI Thread Summary

The discussion revolves around calculating the inductive time constant and resistance in an RL circuit, given that the current reaches half its maximum value in 7.0 seconds. The time constant is defined as τ = L/R, where L is inductance and R is resistance. Participants express confusion about applying this formula correctly and seek clarification on the equation governing current in an RL circuit. The key equation for current in an RL circuit is I(t) = I_max(1 - e^(-t/τ)). Understanding these concepts is crucial for accurately determining the inductive time constant and resistance values.

Jul 9, 2010

clockworks204

1. A current in an RL circuit rises to one half of its maximum value in 7.0s. a) what is the inductive time constant for the circuit? b) if L= 0.8 H, what is the value of the resistance?

2. My book says the (time constant) = L/R

3. I've tried plugging into the above equation, but I know there's something missing, and I don't know what it is.

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Jul 9, 2010

Phrak

What is your equation for the the current in an R-L circuit?

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