A Metal Bar Is Used to Conduct Heat

question 78

Multiple Choice

A metal bar is used to conduct heat.When the temperature at one end is 110°C and at the other is 25°C,heat is transferred at a rate of 20 J/s.The bar is then stretched uniformly to twice its original length.If again it has ends at 110°C and 25°C,at what rate will heat be transferred between it ends?

• A) 5 J/s
• B) 10 J/s
• C) 20 J/s
• D) 40 J/s
• E) 80 J/s