Question

Calculate the value of the shunt resistance when connected across a galvanometer of resistance 18Ω will allow 1/10 th of the current to pass through the galvanometer. 

Answer 1

Here, i_g = `("S"/("S" + 18))"i"`

Given: i_g = `"i"/10`

∴ `("S"/("S" + 18))"i" = "i"/10`

∴ 10 S = S + 18

∴ 9 S = 18

∴ S = 2 Ω

The value of the shunt resistance is 2 Ω.