In the following circuits (Figure 12.2), the heat produced in the resistor or combination of resistors connected to a 12 V battery will be
(a) same in all the cases
(b) minimum in case (i)
(c) maximum in case(ii)
(d) maximum in case(iii)

Solution: The answer is (c) maximum in case(ii)

In this example, two transistors are connected in series. Because they are connected in parallel, the total resistance in figure (iii) will be less than the sum of the individual resistances. Consequently, higher resistance generates more heat, making option c) the correct choice.