Question

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

Answer 1

Here `G=15 Omega, I_(g)=4 mA=.004 A, I=6A`
shunt `S=(I_(g)g)/(I-I_(g))=(0.004xx15)/(6-0.004)=(0.06)/(5.996)=~~10xx10^(-3) Omega=10 m Omega`
So shunt resistance `cong 10 m Omega`.