The best material for making resistances in resistance box (A) Iron (B) silver (C) brass constantan (D)

Wire bond resistances used in resistance boxes are made up of

The resistance of a potentiometer wire is 10 Omega and its length is 10m. A resistance box and 2V accumulator are placed in series with it. The value of resistance in the resistance box, if it is desired to have potential drop of 1 microvolt/mm is

Inside a resistance box various resistance coils are connected

What are the materials generally used for making standard resistance? Give their compositions .

Why are constantan and manganin used for making standard resistances ?

Classify materials on the basis of their resistivities.

The ohmic resistance of a condenser for D.C. current is