Thread: resistance in parallel

1. resistance in parallel

What resistance must be placed in parallel with a 156 resistor to make the equivalent resistance 115 ?

in ohms.

not sure what the equation is.

2. Resistors in parallel:

$\frac{1}{R_1} + ... + \frac{1}{R_{n}} = \frac{1}{R_{total}}$

So for you:

$R_2 = \frac{1}{\frac{1}{115} - \frac{1}{156}} = 438$