@JohnRennie Can I ask another simple thing?

@Abcd yes ... ?

@JohnRennie I have got the right answer but my mind is saying no because:

if the black battery is supportive then why is the green battery like thing not? (supportive in terms of work done to reach B)

green battery like thing is just the equivalent of the inductor behaviour

I just want to know why its not supportive too?

Inductors always oppose current change

Yes thats how I decided the polarity

If the current is decreasing then the inductor will be trying to prevent that decrease.

That's it

????

@JohnRennie Isn't my polarity correct?

Sign of L is positive

and sign of $di/dt$ is negative

But then polarity same side ....

then why is it not supportive

@JohnRennie Did you understand my question?

Hmm, yes, I think the inductor EMF should be in the same direction as the battery ...

That would make the answer 15V

@JohnRennie Yes I have got that...

But my question is different...

I'm not sure I understand what you're asking then. The battery and inductor voltages add to give 20V, and there is a 5V drop across the resistor. So the net voltage between A and B is 15V.

@JohnRennie Voltage across inductor is (L)(di/dt) where both bracketed terms' sign should be taken care of

So for L we have decided +ve

and for di/dt -ve

And $E = -L dI/dt$

@JohnRennie I was just being insane.

@JohnRennie Please trash all my messages starting from here^ till this one.

← 33 messages moved from Problem Solving Strategies

//retcon: "That seems doable" Said Brokhem. [edit: fixed!]

@RobertFrost If a user plans to be here for only one or two days (under one particular account) hoping to get answers to their questions, and NOW, why should they be satisfied, when others remain answerless? Or do you think we should give every user demanding a full step-by-step solution, an answer (typically from the least capable among us)? So they can come back as a "new" user under a different user name to make yet another demand that you think should be satisfied for any "new" user?

← 1 message moved from CRUDE

In any case, @AlexanderGruber o/

@Displayname I was just thinking about that same question: "where is the meta meta.mathematics chat?" :-)

← 2 messages moved from 2018 Moderator Election Chatroom

← 1 message moved from 2018 Moderator Election Chatroom