In an experiment with a post office box, the radio of arms are `1000 : 10`. If the value of the third resistance is `999 Omega`, find the unknows resistance.

Answer

`9.99 Omega`

Explanation

In the given case, the ratio of arms is `1000: 10`.
`(P)/(Q) = (1000)/(10) = 100`
Third resistance is `R = 999 V`.
Lat `X` be the unknows resistance. Then,
`(P)/(Q) = (R )/(X)` or `X = (Q)/(P) xx R = (1)/(100) xx999= 9.99 Omega`