In the arrangements A and B shown in Fig 4.7, pins P and Q are fixed to a metal loop and an iron rod with the help of wax. In which case are both the pins likely to fall at different times? Explain.

Explanation

In the case 'A', the heat moves in both directions So, the pins, P and Q will stop working simultaneously. In the case 'B', the pin P will not succeed before the pin Q. The reason behind is that the heat will reach at pin P first. So therefore, (B).