A 45-mH ideal inductor is connected in series with a 60-Ω resistor through an ideal 15-V DC power supply and an open switch. If the switch is closed at time t = 0 s, what is the current 7.0 ms later?

Question

Physics

Swiss Miss

7 January, 11:03

A 45-mH ideal inductor is connected in series with a 60-Ω resistor through an ideal 15-V DC power supply and an open switch. If the switch is closed at time t = 0 s, what is the current 7.0 ms later?

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Answers (1)

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Melissa Mccann · Answer 1

0.249978A

Explanation:

V = IR + Ve^ (-tR/L)

I = V/R (1-e^ (-tR/L))

R/L = 60/0.045 = 1333.3

e^ (-tR/L) = e^ (-0.007*1333.3) = 0.0000887

I=15/60 (1-0.0000887)

I=0.249978A