A) 20\[\Omega \]
B) 22\[\Omega \]
C) 25\[\Omega \]
D) 28\[\Omega \]
Correct Answer: A
Solution :
Suppose the resistance of voltmeter is R. If the number of divisions on voltmeter scale is N. Then \[\frac{IR}{N}=V\] ?(i) where, \[I=\]current When resistance of 1980\[\Omega \]is connected, then \[\frac{I\,(R+1980)}{N}=100\,V\] ?(ii) On dividing Eq.(ii) by Eq. (i), we get \[R+1980=100\,R\] \[\Rightarrow \] \[R=\frac{1980}{99}\simeq 20\,\Omega \]You need to login to perform this action.
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