Question

1 A piece of wire of resistance R is cut into five
equal parts. These parts are connected in
parallel. If equivalent resistance of this
combination is R, then find the ratio RIR is
1
1
(b)
(d) 25
5
is R If it is cut into 5
(a) 25
(c) 5​

Answer 1

Answer:

25

Explanation:

Wire is cut into 5 equal parts. Since all dimensions are same for pieces, Resistance of each wire is equal and has a value = R/5.

Resistance is proportional to length of wire and inversely proportional to area of cross-section. IF length is 1/5th, then Resistance is also 1/5 th of original value.

When these five are connected in parallel combination, then net resistance becomes 1/5th again. So R1 = R/5 * 1/5 = R/25

Ratio = R1/R = 1/25