# Series circuits question

#### jdr188101

Joined Jan 17, 2016
3
I have a question regarding series circuits with 3 resistors. I have this circuit, and I do my normal testing for voltage, current, and resistance. Each one of the resistors is a 3kiloOhm resistor. Voltage is 12 v system. Schematic wise, I would have resistor 1 on the bottom leg, resistor 2 on the leg adjacent to the voltage source, and resistor 3 on the upper leg (adjacent from resistor 1). If resistor 2 voltage is halved, what would be the cause of this? Would it be resistor 1 open, resistor 1 short, resistor 2 short, or resistor 3 open? I have been wrecking my brain to try and understand this. If anyone could explain it to me, it would be very appreciative.

#### Veracohr

Joined Jan 3, 2011
694
I don't understand your description, post a schematic.

#### WBahn

Joined Mar 31, 2012
24,964
You description of your schematic makes no sense. Are you aware that "adjacent" means "next to" and not "across from"?

Please provide a schematic? Just use boxes with labels in Paint if nothing else.

If they are all in series, then what would the effect be of a resistor going open? Of a resistor being shorted?

#### jdr188101

Joined Jan 17, 2016
3
Its not a great picture by any means

#### WBahn

Joined Mar 31, 2012
24,964
It's perfectly workable for this purpose.

As I suspected, your use of the term "adjacent" is incorrect and, thus, confusing. R1 and R3 are the resistors adjacent to the voltage source and R2 is across from it.

Now, what voltage do you expect to see across R2?

What would you expect that voltage to change to for each of the options you gave?

Do any of them result in the voltage across R2 being cut in half?

#### jdr188101

Joined Jan 17, 2016
3
4 volts across each resistor. And for this exercise, R1 and R3 now have 5 volts.

#### WBahn

Joined Mar 31, 2012
24,964
4 volts across each resistor. And for this exercise, R1 and R3 now have 5 volts.
I agree with 4 V across each resistor before whatever happens happens. But after it happens you only know that the voltage across R2 is 2 V, you have no basis for assuming that R1 and R3 equally share the remaining 10 V.

Take each option in turn and analyze the circuit that results if that condition is what happens.

#### hp1729

Joined Nov 23, 2015
2,304
I have a question regarding series circuits with 3 resistors. I have this circuit, and I do my normal testing for voltage, current, and resistance. Each one of the resistors is a 3kiloOhm resistor. Voltage is 12 v system. Schematic wise, I would have resistor 1 on the bottom leg, resistor 2 on the leg adjacent to the voltage source, and resistor 3 on the upper leg (adjacent from resistor 1). If resistor 2 voltage is halved, what would be the cause of this? Would it be resistor 1 open, resistor 1 short, resistor 2 short, or resistor 3 open? I have been wrecking my brain to try and understand this. If anyone could explain it to me, it would be very appreciative.
So what would happen under each condition?
If in doubt build the circuit and try it.

#### dl324

Joined Mar 30, 2015
9,317
4 volts across each resistor. And for this exercise, R1 and R3 now have 5 volts.
Are you certain that the resistors are all 3K? Measure their resistance (out of circuit) to see.

#### dl324

Joined Mar 30, 2015
9,317
So what would happen under each condition?
If in doubt build the circuit and try it.