If the current reaches a maximum through an inductor of 2A in 15 seconds, what is the current after 3 seconds?
- 1.26A.
- 0.63A.
- 1A.
Explanation
Current in an inductive circuit rises exponentially and reaches its maximum after about five time constants. If maximum is reached in 15s, one time constant is 3s. After exactly one time constant the current equals Imax*(1-e^-1) = 2*0.632 = 1.26A. The 0.63A figure mistakes the fraction for a 1A current.
arifadli8 asking:
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Community Comments (1)
D
dimky Posts: 514 09.01.2014 / 21:16
1 time constant = 15/5 = 3s.
100% charge = 2A, so 1 time constant (63.2%) = 1.26A.
100% charge = 2A, so 1 time constant (63.2%) = 1.26A.
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