Question

In the two 'set-ups' X and Y, shown on the next page, the wires AB and PQR
are made of the same material and have equal thickness. The length of the
wire AB, (in the set-up 'X') is equal to the diameter (= PR) of the semi-circle,
formed by the wire PQR, (in the set-up 'Y'). Pins, P1 and P2, are attached, to
wires AB and PQR respectively, with the help of wax. Which of the two pins,
Pl or P2, will fall off later? Give reason for your answer.​

Answer 1

Answer:

Pin p2 will fall off later.

Explanation:

If we assume the length of wire AB is x, then the diameter of wire PQR is x. Hence the radius is $\frac{x}{2}$. Therefore the length of XYZ is $\frac{\pi x}{2}$.

Therefore, the length of the second wire is greater than the first wire. It takes more time to transfer the heat in the second wire. As a result, the heat generation reaches the wax faster in the small wire. Therefore, pin p2 will fall off later.

Answer 2

Answer:

pin P2 will fall off later