Question

In a meter bridge, null point is at `l=33.7cm`, when the resistance `S` is shunted by `12Omega` resitance the null point is found to be shifted by a distance of `18.2 cm`. The value of unknown resistance `R` should be

A. `13.5Omega`
B. `68.8Omega`
C. `3.42Omega`
D. None of these

Answer 1

`(R)/(S) = (33.7)/(100 - 33.7) rArr (R)/(((12xxS)/(12+S)))=((33.7+18.2))/(100-(33.7+18.2))`
solving get `R = 6.86Omega` .