A) \[20\,\Omega \]
B) \[2\,\Omega \]
C) \[0.2\,\Omega \]
D) \[2k\,\Omega \]
Correct Answer: B
Solution :
Key Idea The potential difference across ammeter and shunt is same. Let \[{{i}_{a}}\] is the current flowing through ammeter and \[i\] is the total current. So, a current\[i-{{i}_{a}}\]will flow through shunt resistance. Potential difference across ammeter and shunt resistance is same. \[ie,\] \[{{i}_{a}}\times R=(i-{{i}_{a}})\times S\] or \[S=\frac{{{i}_{a}}R}{i-{{i}_{a}}}\] ... (i) Given, \[{{i}_{a}}=100\,\,A,\,\,i=750\,\,A,\,\,R=13\Omega \] Hence \[S=\frac{100\times 13}{750-100}=2\Omega \]You need to login to perform this action.
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