Question

Four resistances 4, 4, 4 and 12 ohams form a
Wheatstone's network. Find the resistance
which when connected across the
12ohams resistance, will balance the network.​

Answer 1

Wheatstone bridge condition:

                                        R1/R2 = R3/R4

  R1=4,R2=4,R3=4 ,R4= (12x/12+x)

4/4=4/(12x/12+x)

12X/12+X=4

12X=36+4X

8X=36

X=9

9 ohms resistance must be connected in parallel with 12 ohms