Question

Two diametrically opposite points of a metal ring are connected to two terminals of the left gap of meter bridge. The resistance of 11 Ω is connected in right gap. If null point is obtained at a distance of 45 cm from the left end, find the resistance of metal ring.

Answer 1

R = 11Ω , lx = 45cm

l_r=100-l_x=55cm

Let x be theresistance of metal ring

∴Equivalent resistance in left gap

`1/R_p=1/(x`

`:. R_p=x/4`

From balancing condition

`:.R_p/R=l_x/(100-l_x)`

`(x`

`:.x/4=45/55xx11`

∴ x=9x4

∴x=36Ω