SOLUTION: I am totally confused with this word problem about exectric current i in a circuit containing a resistance R and an inductance L given by ln i/I=Rt/L. t is the time (in seconds) an

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Question 193254This question is from textbook Basic Technical Mathematics
: I am totally confused with this word problem about exectric current i in a circuit containing a resistance R and an inductance L given by ln i/I=Rt/L. t is the time (in seconds) and I is the current at t=0. Calculate in seconds it take the current to reach 0.600 of the initial value if I=0.584A, R=7.44 olms and L=1.41H.
Please help!
This question is from textbook Basic Technical Mathematics

Answer by ejazali_syed(7) About Me  (Show Source):
You can put this solution on YOUR website!
ln i/I=Rt/L
FIrst of all i didnt get this point (the current to reach 0.600 of the initial value, but still im considering it to be 0.6 of initial value)
Calculate in seconds it take the current to reach 0.600 of the initial value if I=0.584A, R=7.44 ohms and L=1.41H.
ANS) i here is the current.
I is the current at time t= 0.
we need to calculate the time in "seconds"
when????
when current reaches 0.600 i.e. i = 0.6 of the initial value.

what is the initial value given I = 0.584A
hence i = 0.6 of I = 0.6*0.584 = 0.3054A
therefore
ln(i/I) = R*t/L ==> ln(0.6*I/I) = 7.44*t/1.41
==> ln(0.6)* 0.1895 = t (in seconds)