Parallel Circuit Question

[MBrown]

Why is the Rt lower in a parallel circuit? I know mathmatically it works out, but that doesn't prove anything to me. Does anyone know why? and Also why is Rt lower than even the lowest resistor in a parallel circuit?

 

[imported_Rat]

What is the Rt lower?

 

[MBrown]

Originally posted by: Rat
What is the Rt lower?

Total Resistance.

 

[dighn]

you can think about it this way. there are more paths for current to go through, and the easiest path to go through (lowest R) has an alternative route to lower it even further

 

[madeupfacts]

Originally posted by: MBrown
Why is the Rt lower in a parallel circuit? I know mathmatically it works out, but that doesn't prove anything to me. Does anyone know why? and Also why is Rt lower than even the lowest resistor in a parallel circuit?

because when u add a parallel connection u r adding an additional path for the electrons to flow. more path 2 travel + the original path = lower resistance.

think of this way. u r driving 2 class on road "A". A has so so so traffic. If u open another
'parallel' road to class that is very heavy in traffic teh overall amount of car u can pass has actually increase. more car can pass quickly just like more electrons can pass quickly

 

[MBrown]

I understand it a little better now. I was just couldnt get passed that. Series made since to me. I have another question instead of doing Pt = 1/[(1/R1) + (1/R2) + (1/R3)..... could you just do Pt = (R1 * R2 * R3)/(R1 + R2 + R3) ?

 

[dighn]

Originally posted by: MBrown
I understand it a little better now. I was just couldnt get passed that. Series made since to me. I have another question instead of doing Pt = 1/[(1/R1) + (1/R2) + (1/R3)..... could you just do Pt = (R1 * R2 * R3)/(R1 + R2 + R3) ?

not equivalent

 

[DrPizza]

Another way to think of it:

get some very fine pieces of wire... If you attach them together end to end, you end up with a longer fine wire - higher resistance. But, if you take a bunch of them and wrap them together, you get a thicker wire which has a lower resistance..

 

[chuckywang]

Parallel - Current splits, Voltage stays the same
Series - Voltage splits, Current stays the same

 

[xrax]

you can think of it as water through a pipe. Higher resistance means thinner pipe. the voltage source would be some sort of pump. The resistance is lower because the water can flow more freely through the additional pipes.

 

[TuxDave]

Originally posted by: MBrown
I understand it a little better now. I was just couldnt get passed that. Series made since to me. I have another question instead of doing Pt = 1/[(1/R1) + (1/R2) + (1/R3)..... could you just do Pt = (R1 * R2 * R3)/(R1 + R2 + R3) ?

Where did you come up with that funky equation? It works well with two resistors:

1/[(1/R1)+(1/R2)] = (R1*R2)/(R1+R2)

Three in parallel will look more like

(R1*R2*R3)/(R2*R3+R1*R3+R1*R2)

 

[Suspicious-Teach8788]

IT's like adding 2 roads that are parallel to each other. Sure you can add one with more resistance (fewer lanes), but in the end you're still speeding up traffic because you're moving overall traffic faster...