How would you join three resistors, each of resistance 9 Ω each such that the equivalent resistance of the combination is

(i) 13 Ω

(ii) 6 Ω

For equivalent resistance = 13 Ω

We have 3 resistor each of resistance = 9Ω

We know that equivalent resistance in series is given on adding all the resistances.

9Ω +9Ω + 9Ω = 27Ω, which is very high as per our requirement i.e. 9Ω And, when connected in parallel, the equivalent resistance is even smaller from the least resistance.

So, here, let add two resistances in parallel :

⇒ Req = 4.5 Ω

Now, lets add the last resistance in series :

⇒ Req = 4.5 Ω + 9Ω = 13.5 Ω

To obtain equivalent resistance of 6Ω

First connect two resistors in series:

⇒ Req = 9 Ω + 9 Ω = 18 Ω

Now, lets, connect these two resistor in series with one resistor in parallel.

Then, Req =