An ammeter has a resistance R and a range I. To increase its range to nL, the resistance that should be connected in parallel with it, is given by

Options

A. `R(n+1)`
B. `R(n-1)`
C. `R/(n-1)`
D. `R/n`

Answer

C

Explanation

`I/(nI)=S/(S+R) therefore 1/n =S/(S+R) thereforens=S+R therefore S=R/(n-1)`