Question

Derive an expression for 3 resistances are connected in parallel combination.​

Answer 1

Answer:

Let the 3 Resistances be named as 'R1' , 'R2' and 'R3' .

Let the Current flowing through the resisitors be 'I1' , 'I2' and 'I3' respectively

As we know ,

V = IR [ According to ohm's law ]

Therefore ,

From the equation ,

I = V/R

Thus ,

I = I1 + I2 + I3

So ,

V/R = V/R1 + V/R2 + V/R3

V(1/R) = V(1/R1 + 1/R2 + 1/R3)  -----> The Potential Difference(V)     is same in a parallel connection

1/R = 1/R1 + 1/R2 + 1/R3

Therefore ,

The expression is : 1/R = 1/R1 + 1/R2 + 1/R3

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