"Theory and Problems of Electric Circuits", 4th edition. McGraw-Hill Companies is also very good text I found in Academia.edu.
In chapter 7 it shows the impulse response of RL circuit.
Mathcad Prime 10 shows it,
I also stand with Mathcad side. Another is unique problem and answer of this book.
My Mathcad Prime sheet shows the answer clockwise current by blue line. Red plot is above answer of clockwise direction. Challenge it.
ACCEPTED SOLUTION
Accepted Solutions
"Theory and Problems of Electric Circuits" is 4th edition. Therefore, auther and millions of readers acsept this very good text book. But, Fig. 16-6's answer is wrong. Table 16-2 red one is also wrong. So, some answers are not correct. Using Prime 10 we can solve it correctly.
I don't know what your blue plot i(t) should show, but is definitely not the function i shown a above!
I guess that t=0 is the time when the switch is switched over to position " 2" after it has been 'long enough' at position "1".
Given the orientation of the source of voltage and the current arrow, at that time the current should be negative, shouldn't it? As inductivity has no effect after 'long enough' time, i(0) = -50V /25 ohm = - 2 A.
So IMHO the ODE should be
It may be an orientation confusion. Electrons go from minus to plus, but current from plus to minus.
But I think that that whatever orientation, the sign of i(0) and i(infinity) should be the same. either -2A and -4 A, or +2A and +4A.
So maybe you meant the blue plot in your graphics to be the correct solution?
Anyway, the solution you show as being the one in the book seems to be wrong in any case. Maybe you should contact the publisher.
BTW, its a pity that the symbolics still is not able to handle units 😞
My point of this thread is the error of this Table. + or - is very confusing if using symbols.
L*i(0) is s*L*i(0)/s easy to understand.
In the Laplace circuit Fig.16-4 (b), initial charge Qo makes Qo/C voltage and should be Qo/sC voltage source not Vo/sC.
To check the Laplace method, Werner_E's ODE method is very usefull becouse it must show the plot of voltage and current responce.
In this case, ODE of the impulse responce of RC circuit is also good problem.
"Theory and Problems of Electric Circuits", 4th edition. McGraw-Hill Companies.
"Theory and Problems of Electric Circuits", 4th edition. McGraw-Hill Companies.
CR Table 7-1(a) has no problem. How to add the impulse's information to odesolve block is a good question for electrical circuit understanding!
The answer of above odesolve is here.
Plot can show impulse of vC+vR at t=0.
The next question is impulse responce of LC series circuit. How to set the initial condition of this odesolve?
In this Mathcad SNS I found the 6th edition of this text still have errror for impulse responce.
Electric Circuits I (Part 2A and 2B). - PTC Community
So millions of readers and also many teachers are bereave wrong electric circuit. I can't find 7th edition of this latest text book in website. May be it show wrong Laplace treatment for electric circuit for 30 years.
Solved: Electric Circuits 1 and II. Part 3D. - PTC Community
Even this text book have some different things for Laplace chapter, this book have very good questions. Challenge this question by Mathcad for both Laplace and odesolve methods.
This is the challenge #8 for Mathcad users of Electrical Engineering students and also teachers.
