Question

. There are three resistors R1, R2 and Rz connected in parallel as shown in the
following figure.
R1-892
11
R2=422
12
R3=222
13
12V
Find the total current drawn from the source of 12V.​

Answer 1

The resistors are connected in parallel.

Therefore,

$\frac{1}{re} = \frac{1}{r1} + \frac{1}{r2} + \frac{1}{r3} \\ \frac{1}{re} = \frac{1}{8} + \frac{1}{4} + \frac{1}{2} \\ \frac{1}{re} = \frac{1 + 2 + 4}{8} \\ \frac{1}{re} = \frac{7}{8} \\ re = \frac{8}{7}$

So, Total resistance (R)=8/7

V=12V

Current(I)=?

By ohm's law:

V=IR

I=V/R

I=12/(8/7)

I=12×7/8

I=10.5 A