A metal bar is used to conduct heat. When the temperature at one end is 100$\degree$C and at the other is 20$\degree$C, heat is transferred at a rate of 32 J/s. The bar is then stretched uniformly to twice its original length. If again it has ends at 100$\degree$C and 20$\degree$C, at what rate will heat be transferred between it ends?
A) 4 J/s
B) 8 J/s
C) 16 J/s
D) 32 J/s

Question

Quizplus · Accepted Answer

When the bar is stretched to twice its original length, its cross-sectional area is reduced, and the rate of heat transfer is inversely proportional to the length. Therefore, the rate of heat transfer is halved twice, resulting in 8 J/s.

A Metal Bar Is Used to Conduct Heat °\degree° C and at the Other Is 20

A Metal Bar Is Used to Conduct Heat $\degree$ C and at the Other Is 20