Question

1.2Amp
40 ohm
20 ohm
calculate the current flowing through each resistor ​

Answer 1

Hi there!

We can begin by finding the equivalent resistance of the parallel segment shown in the diagram.
Recall the following for resistors in parallel:

`(1)/(R_e) = (1)/(R_1) + (1)/(R_2) + ... + (1)/(R_n)`

Plug in the given values for the resistances and solve.

`(1)/(R_e) = (1)/(40) + (1)/(20)\\\\(1)/(R_e) = 0.075\\\\R_e = (1)/(0.075) = 13.333 \Omega`

Now, to solve for the total voltage that will go through this segment, we can use Ohm's Law:

`V = iR\\\\V = 1.2 (13.333) = 16 V`

This is a parallel branch, so 16V goes through each resistor. We can now rearrange Ohm's law equation to solve for current for each resistor.

`i = (V)/(R)\\\\i_(40) = (16)/(40) =\boxed{ 0.4 A}\\\\i_(20) = (16)/(20) = \boxed{0.8 A}`

**Notice that the two currents ADD UP in parallel to the total. Also, this problem can be done more simply using ratios, but this method will help you solve series and parallel combination circuits.