Question

Question 1
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 :
(a) 125
(b) 15
(c) 5
(d) 25​

Answer 1

Answer:

(d) 25​

Explanation:

When we cut the wire into 5 parts, each one has a length of l5 and all other parameters remain unchanged. So the resistance of each new segment isR5. Connecting them parallel gives a network as shown in fig1. So the ratio RR′=25 , which is the required answer