A galvanometer coil has a resistance of `15Omega` and the metre shows full scale deflection for a current of 4 mA. How will you convert the metre into an ammeter of range 0 to 6 A ?

Explanation

1. Here, current capacity of galvanometer is,
`I_(g)=4xx10^(-3)A`
2. Shunt resistance required to convert above galvanometer into an ammeter of current capacity I = 6 A is,
`S=((4xx10^(-3))(15))/((6)-(4xx10^(-3)))`
`thereforeS=0.01Omega`
3. Thus, we should connect `0.01Omega` resistance in parallel with above galvanometer and then we should calibrate its scale from 0 to 6 A in order to prepare required ammeter.