Three metal rods of same lengths and same area of cross-section having conductivities 1, 2, 3 units are connected in series. Then their effective conductivity will be

Three metal rods of same lengths and same area of cross-section having

1.	Three metal rods of same lengths and same area of cross-section having conductivities 1, 2, 3 units are connected in series. Then their effective conductivity will be
Answer» 2 UNITS 1.6 units 2.4 units 2.8 units ANSWER :B