A galvanometer of resistance `16 Omega `shows a full scale deflection for a curent of 20 mA. The only shunt resistance that is available is `0.06 Omega` but it is not sufficient into an ammeter having a range of 8A. How much resistance should be connected in series with the galavanometer to get the ammeter of the desired range?

Options

A. `7.94 Omega`
B. `8.94 Omega`
C. `8.94 Omega`
D. `6.94 Omega`

Answer

A

Explanation

Let x be the resistance to be connected in seriess with G.`I_g/I=S/(S+(G+X))therefore S+G+X=(I(S))/I_g=8/(20 xx 10^(-3))xx6/100=400 xx 6/100=24 Omega`.