Question

how to combine the three resistance 4om , 8 om , 12 om such that their resultant resistance become (1) maximum value (2) minimum value

Answer 1

If you connect two of the resistors in series, and then connect these two in parallel with the other resistor, you’ll get a combined resistance of 6 ohms.

1/Req = 1/R1 + 1/R2

1/Req = 1/(9 + 9) + 1/9

1/Req = 1/18 + 2/18

1/Req = 3/18

Req = 18/3 = 6 ohm

Answer 2

Resistance become maximum when connected in series and resistance become minimum when connected in parallel combination.

In series ,

Rs= 4 + 8 +12

Rs=24ohm

In parallel ,

1/Rp= 1/4 +1/8 +1/12

1/Rp= 6 +3 +2 /24

1/Rp=11/24

Rp=24/11

Rp=2.18 ohm