With the help of a circuit diagram, obtain the relation for the equivalent resistance of two resistances connected in parallel.
Let the individual resistance of the two resistors be R1 and R2 and their combined resistance be R. Let the total current flowing in the circuit be I and strength of the battery be V volts. Then, from Ohm's law, we have: V= IR... (1)
We know that when resistors are connected in parallel, the potential drop across each resistance is the same. Therefore: =I=I1 + I2 = V/R1 + V/R2
I = V/(1 /R1 + 1/R2) ... (2)
From the equations (1) and (2) we have:
1/R = 1 /R1 + 1/R2
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