Question

A piece of metallic wire of resistance Ris cut into 3 equal parts. These parts are
then connected in parallel. If the total resistance of this combination is R', then
the value of R: R' is
(A)
1:3
(B) 9:1
(C)
1:9
(D) 3:1.​

Answer 1

Answer:

Option C. is right 1:9

Explanation:

1:9

each resistance=R/3

In parallel,1/r=3/R+3/R+3/R

1/r=9/R

∴R:r=1:9

Answer 2

Answer:

(B)9:1

Explanation:

as R is cut into 3 parts, each part equals 3/R

therefore, R' = 3/R + 3/R + 3/R = R/9

so, R/R' = R/R/9

= 9:1