r = resistance of the galvanometer
l = current through galvanometer = 1mA or 0.01A
V1 = p.d across the galvanometer = I X r = 0.01 X r
: V1 = 0.01r
V2 = p.d across the multiplier = 5 - 0.01r
where R = VI\frac{V}{I}IV --> 498 = 5−0.01r0.01\frac{5 - 0.01r}{0.01}0.015−0.01r
CROSS MULTIPLY --> 498 X 0.01 = 5 - 0.01r
0.01r = 5 - 4.98
∴ r = 0.020.01\frac{0.02}{0.01}0.010.02 = 2Ω
