A galvanometer having `30` divisions has a current sensitivity of `20muA//di vision`. It has a resistance of `25Omega`. How will you convert it into an ammeter upto 1 ampere? How will you convert this ammeter into a voltmeter up to 1 volt?

Explanation

The current required for full scale deflection `I_(g)=20muAxx30= 600muA=6xx10^(-4)A`
(i) To convert it into ammeter, a shunt is required is parallel with it
Shunt resistance `R'_(s)=(I_(g)R_(g))/((I-I_(g)))=((6xx10^(-4)) /1-6xx10^(-4))25= 0.015Omega`
(ii) To convert galvanometer into voltmeter a high resistance in series with it is required
series resistance `R=(V)/(i_(g))-R_(g)=(1)/(6xx10^(-4))-25=1666.67-25=1641.67Omega`