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 16 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 decreases, which affects the rate of heat transfer. The rate of heat transfer is inversely proportional to the length of the bar and directly proportional to the cross-sectional area. Since the length is doubled and the area is halved, the rate of heat transfer becomes one-fourth of the original rate, which is 4 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