Experiments of meter bridge

It is a device based on wheat stone bridge it consist of 1 m long straight and uniform wire AC The wire is made up of manganin constantan because they have low temperature coefficient and large resistivity. Wire are soldered to two thick 1- shaped copper strips with binding terminal on a wooden board between these 1-shape strips there is a third copper strip. Thus between the strips there are two fixed gap Ab and CD in meter scale is also tittled on the wooden board parallel to the length of wire Across 1 gap a resistance box R and another gap the unknown resistance S are connected a jockey B can be slided on the bridge wire one terminal of the sensitive galvanometer is connected to jockey B and the other to the terminal D the positive terminal of the battery E is connected to terminal A and negative pole of the battery to come battery to terminal c through a one way key k. This circuit is now same as that wheat stone bridge.