Question

A galvanometer having resistance of 20 ohm and 30 divisions

Answer 1

For about 30 divisions there will 10ma per division like (30*10) - 300mA FSD meter of resistance. with 20R.

Therefore to determine there will be resistance of a galvanometer like

Rb = 20 ohms

N= 30 (on both sides)

From the figure of merit = 1/Ф = 0.005 A/dv

The current sensitivity is = (1/0.005) = Ф/1

Hg(max) = 0.005*30

15*10-2 = 0.15

15=0.15(20+R)

R = 80 ohms.