Question

a metallic wire of resistance R is cut into 10 equal part 2 pieces are joined in series and 5 such combination in parallel what will the effective resistance of the combination

Answer 1

The effective resistance will be R/25

Answer 2

a metallic wire of resistance R is cut into 10 equal parts
resistance of each part = R/10

2 pieces are joined in series
resistance of this = R/10 + R/10 = 2R/10 = R/5

5 such combination in parallel
let the resistance of this combination = r

1/r = 5/R + 5/R + 5/R + 5/R + 5/R

or 1/r = 25/R

or r = R/25

hence, resistance of the combination is R/25