## Equivalent Resistance Formula :

Equivalent resistance formula series resistance R_{(1=V/A)} in volt per ampere is equal to product of R1 + R2+ …………………R_{n }(Ω) in ohm. Hence the equivalent resistance series formula has been written as,

**R _{(1=V/A)}= R1 + R2+ …………………R_{n }(Ω)**

Equivalent resistance formula parallel resistance is given by,

Equivalent resistance formula parallel resistance 1/R_{p(1=V/A)} in volt per ampere is equal to product of 1/R1 + 1/R2+ …………………1/R_{n }(Ω) in ohm. Hence the equivalent resistance parallel formula has been written as,

**1/R _{P(1=V/A) }= 1/R_{1} + 1/R_{2} + 1/R_{3 }+ ………..+ 1/R_{n }(Ω)**

Where,

R1,R2……..R_{n} the given resistors.

## Sample Sums :

### Sum 1 :

Calculate the equivalent resistance if 2 Ω,and 23 Ω and 30 Ω are connected in series?

### Solution :

Equivalent resistance series in is given by,

R= R1 + R2+ …………………R_{n }(Ω)

= 2 Ω + 23 Ω + 30 Ω

= 55 Ω

### Sum 2 :

Calculate the equivalent resistance if 30 Ω and 25 Ω are connected in parallel?

### Solution :

Equivalent resistance in parallel is given by,

1/R_{P }= 1/R_{1} + 1/R_{2} + 1/R_{3 }+ ………..+ 1/R_{n }(Ω)

1/R_{P }=1/30+ 1/25

1/R_{P }= 0.0733

(or)

R_{p}=R_{1} R_{2 }/ R_{1+} R_{2}

R_{p }=13.63 Ω