Look at Figure 4.9. Fig. 4.9
The length of wire PQ in case of A is equal to the diameter of the semicircle formed by the wire CDE, in case B. One pin is attached to each wire with the help of wax as shown in Figure 4.9. Which pin will fall first? Explain.
Pin on the wire in fig A will fall first since we know that heat travels by conduction in solid and the distance (which is PQ) is less in fig A as compared to fig B (which is CE) so heat reaches pin in fig A faster and makes it fall down.