A galvanometer of `25 Omega` resistance can read a maximum current of 6 mA . It can be used as a voltmeter to measure a maximum of 6 V by connecting a resistance to the galvanometer. Identify the correct choice in the given answers

Options

A. `X=575 Omega` in series
B. `X=800 Omega` in parallel
C. `X=975 Omega` in parallel
D. `X=975 Omega` in series

Answer

D

Explanation

`i_(max)=6 xx 10^(-3)A`. To convert it into a voltmeter to read upto 6V, a high resistance xx is joined in series with the galvanometer coil. Resistance of the voltmeter,`R=V/i=6/(6 xx 10^(-3))=1000Omega thus R=G+X therefore 1000=25+X therefore X=975Omega`Thus a resistance of 975 Omega is joined in series.