Experimental Skills (Physics)

In the experiment to determine the galvanometer resistance by half-deflection method, the plot of 1/ vs the resistance (R) of the resistance box is shown in the figure. The figure of merit of the galvanometer is 10-1 A/division. [The source has emf 2 V] [figure]

Answer

5

Solution

I = K = ER + G (K = figure of merit, G = galvanometer resistance)

1 = KER + KGE — a straight line of slope KE

Slope = 2 - 126 - 0 = 14 div-1 -1

K = E 14 = 24 = 0.5 A/div = 5 10-1 A/div

Answer: 5