- #1

fourthindiana

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- TL;DR Summary
- Will electrical current flow through all the resistors in the parallel circuit in the attached photograph?

Preface to thread: The "closed switch" in this ladder diagram is a normally closed contactor. Sometimes when I post photographs of ladder diagrams with this symbol on them, people sometimes mistakenly assume that the switch is a variable capacitor. That's why I am letting everyone know that the normally closed switch is a normally closed contactor.

___________________________________________________________________________________________________________________________________________I'm a student attending a HVAC program at a trade school. In the photograph of a ladder diagram attached to the top of this post, my instructor says that electrical current will only flow through the 200-Ohm resistor. My instructor says that no electrical current whatsoever will flow through the 100-Ohm resistor. My instructor says that "electricity is lazy", and my instructor says that the electricity will take the shortest possible path from line 1 to line 2. Therefore, since electricity will take the shortest possible path from line 1 to line 2, electricity will bypass the 100-Ohm resistor and go straight from line 1 through the 200-Ohm resistor and to line 2.

We have an electrical wiring training board at the trade school. My instructor wired up a parallel circuit that my instructor said was exactly the same as the ladder diagram I attached at the top of this post. I put my amp clamp on the wire that was equivalent to the wire that goes to the 100-Ohm resistor, and my amp clamp measured 0.0 amps. But perhaps my meter resolution was too low to pick up on current. However, my instructor told me that not one electron of current will flow through the 100-Ohm resistor.

I thought I understood what my instructor was saying about how electricity would flow in a circuit with the attached ladder diagram until I thought about an exchange of messages I had on Physics Forums back in December of last year on a thread I created with a title similar (but not exactly the same) to this title of this thread. The thread I created back in December 2018 is titled "Reconciling an apparent contradiction about parallel circuits". My "Reconciling" thread back in December was about parallel circuits with digital multimeters in them. In my "Reconciling" thread back in December, pf member Borek told me that electrical current will flow through all resistances in a parallel circuit. Nobody else on the thread disagreed with what Borek said.

What Borek told me indicates that current would flow through the 100-Ohm resistor. My instructor says that no current whatsoever would flow through the 100-Ohm resistor.

Who is correct, Borek or my instructor?

In the parallel circuit in the ladder diagram in the photograph attached at the top of this post, will any electrical current flow through the 100-Ohm resistor?

Please explain your answer.

If you say that electrical current will flow through the 100-Ohm resistor, how can I prove this to my instructor using the electrical wiring practice board at the trade school?----------------------------------------------------------------------------------------------------------

Here is a link to the "Reconciling" thread I created back in December of last year. Borek's post is post #4 in this thread.