A resistance of 90 `Omega` is connected in series with a galvanometer of resistance 100 `Omega` A potential difference of 1 V produces a deflection of 100 divisions in the galvanometer. Find the figure of merit galvanometer.

Explanation

`G = 100 Omega`
`R = 90 Omega`
`V= 1` volt
Figure of Merit, `k = ?`
`R = (V)/(I_(G)) - G`
`90 = (1)/(I_(G)) -100`
`(1)/(I_(G)) = 100 + 90 = 190`
`I_(G) = (1)/(190) = 0*00526A`
`I_(G) = 5*26 xx 10^(-3)A`
As potential difference of 1 V produces a deflection of 100 divisions in the galvanometer.
No. of divisions = n = 100
`k = (I_(G))/(n) = (5*26 xx 10^(-3))/(100)`
`=5*26 xx 10^(-5) A "division"^(-1)`