A thin uniform wire `AB` of length `1 m`, an unknown resistance `X`, and a resistance of `12 Omega` are connected by thick conducting strips, as shows in Fig. `6.27`. A battery and a galvanometer (with a sliding jockey connected to it) are also available. Connections are to be made to measure the unknows resistance `X` using the principle of wheatstone bridge. Answer the following question.

(i) Are three positive and negative terminals on the galvanometer ?
(ii) Copy the figure in your answer book and show the battery and the galvanometer (with jockey) connected at appropriate points.
(iii) After appropriate connections are made, it is found that no deflection takes place in the galvanometer when the slider jockey touches the wire at a distance of `60 cm` from `A`. Obtain the value of the resistance `X`.

Explanation

AJ=60 cm , `therefore BJ=40 cm`, IF no deflection is taking place. Then, the Wheatstone’s bridge is said to be balanced.
Hence , `X/12=R_(BJ)/R_(AJ) or X/12=40/60=2/3 or x=8 Omega`