Q.
Four resistors A,B,C and D form a Wheatstone bridge as shown in the figure. The bridge is balanced when C=100Ω. If A and B are interchanged, the bridge balances for C=121Ω. The value of D is
According to the question, balanced wheat stone bridge, can be shows as follows First case when, C=100Ω
Now, By balanced wheat stone bridge, RBRA=R100...(i) Second case when, C=121Ω RARB=R121...(ii)
From Eqs. (i) and (ii), we get ∴R=100×121 R=110Ω