How do you calculate resistance in series and parallel circuits?

Answer 1

when in series you can use this: R1+R2+R3+enz=you total resistance.

and when in parallel you can use this: Req = 1 / (1/R1+1/R2+1/R3+1/R4+enz).

If there are 2 resistors in parallel, use Product over sum: Req = R1*R2/(R1+R2).

For 3 resistors, a little more tricky: Req = R1*R2*R3/(R1*R2 + R1*R3 + R2*R3). For more than 3, use the general formula above for a quantity of resistors in parallel.

Answer 2

There are two rules, one for each configuration.

They are:

-- The resistance of the series combination of several resistances is the sum

of the individual resistances.

-- The resistance of the parallel combination of several resistances is the reciprocal

of the sum of the reciprocals of the individual resistances.

Answer 3

To get the equivalent resistance:

If two or more resistors are in series, add the resistance values. Rt = R1 + R2 + R3 ...

If two or more resistors are in parallel, use the formula 1 / Rt = 1 / R1 + 1 / R2 + 1 / R3 ... In other words, add the reciprocals of all the resistance values, then take the reciprocal again.

Answer 4

To get the equivalent resistance, just add the individual resistances, those that are in series.