The range of an ammeter of resistance G can be increased from I to nI by connecting,

Options

A. a parallel resistance of G/n
B. a series resistance of Gn
C. a parallel resistance of G/(n-1)
D. a series resistance of G(n-1)

Answer

C

Explanation

To increase the range from I to nI a parallel resistance (shunt S) is connected across the galvanometer.`I_g/I=S/(S+G)=I/n therefore nS=S+G thereforeS(n-1)=G thereforeS=G/(n-1)`.