A) 4R
B) \[\frac{R}{3}\]
C) \[\frac{R}{4}\]
D) \[\frac{R}{5}\]
Correct Answer: B
Solution :
Key Idea: Shunt is connected in parallel with galvanometer. Ammeter is made by connecting a low resistance shunt 5 in parallel with galvanometer G. Since G and 5 are in parallel, the potential difference across them is same \[{{i}_{g}}\times G=(i={{i}_{g}})\times S\] Given, \[G=R,\,\,i=4\,{{i}_{g}}\] \[\therefore \] \[S=\frac{{{i}_{g}}}{4\,{{i}_{g}}-{{i}_{g}}}\times R=\frac{{{i}_{g}}}{3\,{{i}_{g}}}\times R=\frac{R}{3}\] Note: Resistance of shunt is always low.You need to login to perform this action.
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