A galvanometer has a coil of resistance 100 showing a full scale deflection at 50 A . The resistance that should be added to use it as an ammeter of range 10 ~mA is

Step-by-step solution

Given, Resistance of galvanometer aligned R_g & =100 I_g & =50 A =5 10⁻⁵ ~A I & =10 ~mA =10⁻² ~A R_s & =? aligned We know that, R_s= I_g I-I_g R_g . aligned & = 5 10⁻⁵ 10⁻²-5 10⁻⁵ 100 & = 5 10⁻³ (1000-5) 10⁻⁵ = 5 10^2 995 & = 500 995 =0.503 & 0.5 aligned