091120 | Current Electricity

(a) Differentiate between electrical resistance and resistivity of a conductor.
(b) Two metallic rods, each of length L, area of cross A1 and A2, having resistivities ρ1 and ρ2 are connected in parallel across a d.c. battery. Obtain the expression for the effective resistivity of this combination.
[2020 | Delhi | Section - C | SET - 1 SET - 3, Q.28 Q.33]