Question

Three resistors 10ohm,20ohmand 30ohm are connected on parallel,then find out effective resistance

Answer 1

Question.

Three resistors 10ohm,20ohmand 30ohm are connected on parallel,then find out effective resistance

Answer.

Formula.

find total resistance in a Parallel circuit with the following formula: 1/Rt = 1/R1 + 1/R2 + 1/R3 +...

So R1=10 ohm

R2=20 ohm

R3=30 ohm

So total effective resistance =1/20+1/30+1/10

=5/60

1/R

=1/12ohm

So R= 12ohm

Answer 2

$\underline{\bold{Given:-}}$

Three resistors of resistance 10 ohm, 20 ohm and 30 ohm are connected in parallel.

$R_{1} = 10 \: ohm$

$R_{2} = 20 \: ohm$

$R_{3} = 30 \: ohm$

$\underline{\bold{To\: find:-}}$

The effective resistance $R_{p}\: ohm$.

$\underline{\bold{Solution:-}}$

Expression for parallel effective resistance

$\frac{1}{ R_{p} } = \frac{1}{ R_{1} } + \frac{1}{ R_{2}} + \frac{1}{ R_{3} }$



$\frac{1}{ R_{p} } = \frac{1}{10} + \frac{1}{20} + \frac{1}{30} \\ \\ \frac{1}{ R_{p} } = \frac{6 + 3 + 2}{60} \\ \\ \frac{1}{ R_{p} } = \frac{11}{60} \\ \\ R_{p} = \frac{60}{11} ohm$