how does individual resistance in parallel measured?

Answer 1

What do you mean by "individual resistance in parallel"? Are you asking how you measure the resistance of a single resistor that is connected to a parallel circuit?

If that is the case, you can't. There is no way to measure the correct resistance of one resistor when it is connected to a parallel circuit. You will have to disconnect it from the circuit to measure it.

Edit: Kirchhoff's Law and Ohm's Law will work to calculate the resistance of a single resistor in a parallel circuit but the question was (I think) "how do you measure it?" not "How do you calculate it?" And some resistances may not be easily marked, such as the resistance of a relay winding.

In a parallel circuit, the only way to accurately measure the resistance of a single component is to remove that component from the circuit. You can do that by disconnecting a single contact on that component.

Answer 2

Kirchoff's law for paralle circuits:
In a parallel circuit the Voltage stays the same across each resistor and the total current divides up between each resistor by on the value of each resistance.

So to find the total current you must first find the total equivalent resistance.

for resistors in parallel there are three methods.

1.) if all resistors are equal in value then take 1 value and divide it by the number of resistors.

2.) if you have 2 resistors in parallel that are different use
the product over the sum
(r1*r2)/(r1+r2) = r equivalent

3.) for more than 2 resistors in parallel that have different values
take the reciprocal of the sum or the reciprcals

1/( 1/r1 + 1/r2 + 1/r3 ...)) = r equivalent

Once you have figured out an equivalent total resistance and you know the voltage across it use ohms law to compute the total current.

Then you can split the total current proportionally across the resistor values or use additional ohms law computations for individual current flows

Answer 3

Hi >
Oh dear, it seems your question is not fully understood.
I don't understand it either !
I would comment & agree that you need to remove the individual resistor, and bung it across a decent meter, as if it is still in a circuit of some sort, you ain't got a clue.
If you mean a set of resistors, though, if in series for some reason - "why not use a higher value"? , but add them up.
If you have resistors in parallel, then use recipricles. Such as two 1kOhms mateys will give you 500Ohm on that bit of the circuit.
Why not use a 500 in the first place ?
So remove the things, and give them a proper measure.
All the best,
Bob.

Answer 4

The current through each branch of the parallel resistor combination is divided in inverse proportion to the resistance of the individual resistor.

With a constant voltage accross the pair, the current through one resistor would be V/R1, the current through the other would be V/R2.

The total current would be the sum of (V/R1) + (V/R2)

I = (V/R1) + (V/R2) = V( (1/R1) + (1/R2) )

Since resistance is current divided by voltage, we can re-arrange the above equation in terms of I / V to give:

I / V = 1 / ( (1/R1) + (1/R2) )

You can apply this to any number of resistors of any values in parallel.

Cheers.

Answer 5

as above