A) 5\[\Omega \]
B) 3.33\[\Omega \]
C) 4.6\[\Omega \]
D) 2.33\[\Omega \]
Correct Answer: D
Solution :
It is evident from the diagram that between \[{{J}_{1}}\] and \[{{J}_{2}}\]there will be a point J such that when the jockey is made to touch J, there will be no deflection in the galvanometer. As per principle of potentiometer when a constant current is passed through a wire of Uniform cross-section the potential difference across any portion of wire is directly proportional to the length. \[E=Kl\] First case, \[\frac{E}{2+R}\times 2=300\,K\] Second Case, \[\frac{E}{2+R}\times R=350K\] \[\therefore \] \[\frac{R}{2}=\frac{350}{300}\] \[\Rightarrow \] \[R=2.33G\Omega \]You need to login to perform this action.
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