A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R', then the ratio R/R' is:

The resistance of wire is R. This wire is cut into five equal pieces. The resistance of each piece of the wire will be R_{1}, R_{2}, R_{3}, R_{4} and R_{5} respectively. Now, when these five pieces are connected in parallel, the equivalent resistance for the combination is R’. We can write,

Thus, the correct answer is: Option (d)

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