Question

show how would u join three resiators .each resistance 9ohm so that the equivalent resistance of the combination is (1).13.5ohm.(2).6ohm.

Answer 1

1) join R¹ and R2 in parallel

1/rp=1/9+1/9=2/9

Rp =9/2

And join it with 3rd resistor in series

Rs=9/2+1/9=9+18/2

27/2=13.5 ohm

For 6 ohm resistance

Join R¹ ,R2 in series and R3 in parallel with r1 and R2

Resistance in series =9+9=18 ohm

Resistance in parallel =1/18+1/9=1+2/18=3/18

Rp/1=18/3=6ohm