Two metallic rods are connected in series. Both are of same material of same length and same area of cross-section. If the conductivity of each rod be k, then what will be the conductivity of the combination ?

Options

A. 4 k
B. 2 k
C. k
D. `k//2`

Answer

C

Explanation

We use `k_(eq) =(2 k_(1)k_(2))/(k_(1)+ k_(2))`
As `k_(1)=k_(2)=k`
`rArr k_(eq) =(2k^(2))/(k+k) =k`