Hi all,

IF R1=13Ω, R2=42Ω R3=???Ω.


V=230Volts & I=53amps.


Calculate R3


Im familiar with using Volts & Amps to get Resistance Total, but not sure with above when given 2 of the 3 resistance values.


Using V & I to calculate I get:


Rt = 4.339622Ω


I thought it would make sense(in my head to) then -R1 & R2 values from Rt to give R3??
Is this correct?? Thx

 

Hello,

You can take an other approach to the problem.
You know the total current.
You know two resistor values.
With the given voltage and the two given resistors,
you can calculate the currents through these resistors.
You can subtract the calculated currents from the total current.
With this resulting current and the given voltage,
you can calculate the missing resistor value.

Succes,
Bertus

 

 

Thx for replies..
The circuit is identical to the one you provided,
Just to clarify I will not be building this circuit, it was a question from a past exam that I have been studying & trying to familiar myself with,
thanks for your time guys..

 

Hello,

@dcarson7:
The homework help forum is to get help.
Please do NOT give complete answers anymore.
Only hints and suggestions to solve the problem are welcome.

@stinky111
You can take a look at this page of the eBook:
Simple parallel circuits

Bertus

 

I would not be too quick to say that this is a ridiculous example, by the way. An electrical heating application could easily use this much power. The "resistors" could represent heating elements in something like a big water heater. http://www.pexsupply.com/Argo-AT0824-8KW-Two-Element-Electric-Boiler-27000-BTU-11329000-p

 

@bertus - Advice noted. , when I said check RT with R3 value, I was hinting for the OP to make some effort there.
There was nothing asked regarding power but I felt it'd be wise to inform someone new that considerations needed to be made.

@Adjuster - solid point, anything high power I tend to run away from