A) 0.1\[\Omega \] in parallel
B) 0.1\[\Omega \] in series
C) 0.2\[\Omega \] in parallel
D) 0.2\[\Omega \] in series
Correct Answer: A
Solution :
Key Idea: An ammeter is made by connecting a low resistance in parallel with a moving coil galvanometer. A galvanometer as such cannot be used as an ammeter, because it has appreciable resistance and it can measure only a limited current. In practice, an ammeter is made by connecting a low resistance in parallel with G. The potential difference across G and S is same \[\therefore \] \[{{i}_{g}}\times G=(i-{{i}_{g}})\times S\] \[\Rightarrow \] \[S=\left( \frac{i}{i-{{i}_{g}}} \right)G\] Putting the numerical values, we have \[S=\left( \frac{0.01}{10-0.01} \right)\times 100=0.1\Omega \]You need to login to perform this action.
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