What's the resistance across AB?

 

What's the resistance across AB?

12//4= 3
the two resistors are connected in parallel..connected across same 2 points A and B.
think, when can u actually say those are in series?

 

Simple. Resistors are in parallel. Resistance is 3Ohm.

 

Yeah yeah, they're in parallel -- I realized that after posting. But a neophyte like myself thought they were in series... I mean, come on, it looks just like a pair of series resistors!

 

Yeah yeah, they're in parallel -- I realized that after posting. But a neophyte like myself thought they were in series... I mean, come on, it looks just like a pair of series resistors!

I noticed it too. The way the circuit is designed is misleading.

 

One comes across such situations often in network analysis...and it is really funny since u can assume without regret that one person out there is sure to commit a mistake there and u can look smart explaining it to him. Meaning i perhaps made a similar mistake once.

For the resistors to be in series one must encounter both resistance when traversing the wire from point A to B at once.

 

For the resistors to be in series one must come encounter both resistance when traversing the wire from point A to B at once.

Indeed, its quite deceptive. It is often best in circumstances such as these to redraw the circuit in order to confirm that your suspicions are indeed correct. As is the case with learning in electronics we are conditioned to expect circuits to be drawn in a certain way.

Dave

 

If it is a text book problem than it is an old trick. Teaches one not to assume anything. The best thing to do is try redrawing the circuit by tracing out the current paths.

 

What are you talking about?
The resistors are obviously in parallel.

 

What are you talking about?
The resistors are obviously in parallel.

Were they obvious the very first time you seen that circuit those years ago?

Recently I spoke with a newbie [not a poster of this forum] who didn't "see" a parallel resistor path. It's not obvious to the newbie. Just as asimov stated

If it is a text book problem than it is an old trick. Teaches one not to assume anything.

As an experienced person, you should not assume the obvious to you is the obvious to everyone.

 

I was a noobie such a long time ago that today I can't remember being a noobie.

 

I was a noobie such a long time ago that today I can't remember being a noobie.

It's been so long since I was a newbie that I suffer from CRS ... Cant Remember S_it.