Show four different ways in which four resistors of $r\ \Omega$ each may be connected in a circuit. In which case is the equivalent resistance of the combination:

(i) maximum;

(ii) minimum?

Hint

The equivalent resistance of a series circuit is the sum of the individual resistances.

Quick oral answer

The equivalent resistance of a series circuit is the sum of the individual resistances. In case (i), the equivalent resistance is $4r$. In case (ii), the equivalent resistance is rac{r}{4}. Therefore, the equivalent resistance of the combination is maximum in case (i) and minimum in case (ii).