A galvanometer whose resistance is `120 Omega` gives full scale deflection with a curretn of `0.5 A` so that it can read a maximum current of `10 A`. A shunt resistance is added in parallel with it. The resistance of the ammeter so formed is

Options

A. `0.06 Omega`
B. `0.006 Omega`
C. `0.6 Omega`
D. `6 Omega`

Answer

C

Explanation

(c ) Resistance of shunted ammeter `= (GS)/(G + S)`
Also `(i)/(i_(g)) = 1 + (G)/(S) implies (GS)/(G + S) = (i_(g). G)/(i)`
`implies (GS)/(G + S) = (0.05 xx 120)/(10) = 0.6 Omega`