P2.9 Many years ago a string of Christmas tree lights was manufactured in the form shown in Fig. P2.9a. Today the lights are manufactured as shown in Fig. P2.9b. Is there a good reason for this change?
FigureP2.9
2.9
figure2.9
In figure 2.9(a) the Christmas tree lights are connected in series .if open circuit bulb fails then remaining bulbs also fails (or) turn off so no current flows through the circuit.
In figure2.9(b) ,the Christmas tree lights are connected in parallel .If the open circuit bulb fails then also other bulbs will works properly .In parallel connection the open circuit bulb will not effect the other bulbs.