In a meter bridge as shown in figure, the balance point is found to be at 39.5 cm from the end A, when the Y resistor is of 12.5`Omega`. Determlne the resistance of X. Why are the connections between resistors in a Wheatstone or meter bridge made of thick copper strips ?

Explanation

For equilibrium condition
`(x)/(y) = (l_(1))/(100 - l_(1))`
`therefore (x)/(12.5) = (39.5)/(100 - 39.5)`
`therefore x = (39.5)/(60.5) xx 12.5 `
`therefore x = 8.16 Omega`
Reason for using thick metallic strips in Wheatstone bridge and meter bridge is that their resistances are extremely small which can be easily neglected as compared to those connected in the two gaps.