Resistors in parallel

When resistors are connected in parallel, the amount of the voltage drop across all the resistors is same but the current passing though the resistors varies depending on their resistance values. For parallel connected resistors the equivalent resistance is equal to inverse of the sum of inverse resistances in parallel. Thus for a parallel connection of resistors, equivalent resistance decreases with increase in number of resistors in parallel.

Consider the following
circuit of three resistors of resistance R₁,R₂ and R₃ respectively connected in parallel.

resistors in parallel

The below circuit shows the equivalent circuit with their equivalent resistance which is given by R_eq^-1= R₁^-1+R₂^-1+R₃^‑1 or \[\frac{1}{R_{eq}}=\frac{1}{R_{1}}+\frac{1}{R_{2}}+\frac{1}{R_{3}}\] 

equivalent resistance

Similarly, if there n resistances each of resistance R are connected in parallel then their equivalent resistance is R/n.