Question

A moving coil galvanometer, having a resistance G, produces full scale deflection when a current Ig flows through it. This galvanometer can be converted into (i) an ammeter of range 0 to I₀ (I₀ > Ig) by connecting a shunt resistance RA to it and (ii) into a voltmeter of range 0 to V(V = GI₀) by connecting a series resistance RV to it. Then,

Answer 1

Answer:

i am in class 11

how can i solve it

Answer 2

RaRv = G² and (Ra/Rv) = (Ig/(Io-Ig))²

• Case 1: Galvanometer is converted to ammeter
•  Shunt resistance is used in parallel with galvanometer when galvanometer is used as an ammeter

            IgG=(Io-Ig)Ra

           Ra=IgG/(Io-Ig)…………(1)

• Case 2:  Galvanometer is converted to voltmeter

• Shunt resistance is used in series with galvanometer when galvanometer is used as a voltmeter

          Ig(G+Rv) = V = G×Io

          Rv = (Io-Ig)×G / Ig……………(2)

• By solving equations 1 and 2 we get

          RaRv = G²

         (Ra/Rv) = (Ig/(Io-Ig))²