CLASS 12TH PHYSICS EXPERIMENT To determine resistance of a galvanometer by half deflection method and to find its figure of merit.

To determine resistance of a galvanometer by half deflection method and to find its figure of merit. Aim: To determine resistance of a galvanometer by half deflection method and to find its figure of merit. Apparatus: Moving coil galvanometer , two resistance boxes , two one way keys , connecting wires , sand paper and a battery. Theory: To find resistance of galvanometer (G) Galvanometer of resistance G when connected in series with a resistance R and a battery of emf E , the current is I=E/(R+G) if š¹ is the deflection. K š¹ = E/(R+G) Now such a resistance S is connected in parallel with G , that the deflection becomes half i e š¹/2, then K( š¹/2) = E/(R + (GS/(G+S)) Using K š¹ in this we have E/(R+G)2 = E(G+S) / R (G + S ) + GS , on solving G = RS/ (R-S) Half deflection method Class 12th Physics Practical To find figure of merits (k) Figure of merit is current per unit deflection i e , k=I/ š¹ k= I/ ?...