Passage VII
When a temperature difference (△T) exists between the ends of an insulated metal rod (see Figure 1), heat flows from one end of the rod to the either. (△T = TH - TC, where TH and TC represent the temperature of the hotter end and the colder end, respectively.)
The rate at which heat flows is called the heat transfer rate, R.
The following data apply to insulated copper rods. Table 1 gives R versus △T for a 5 cm long rod with a cross-sectional area of 3 cm2. In Figure 2, R is plotted against length for rods having a △T of 30℃ and a cross-sectional area of 3 cm2. In Figure 3, R is plotted against cross-sectional area for 5 cm long rods with a △T of 30°C.
38. For any of the rods described in the passage, most heat is transferred between the ends of the rod by which of the following processes?
Ⅰ. Radiation
Ⅱ. Convection
Ⅲ. Conduction
Your Answer is
Correct Answer is H
Explanation
General knowledge questions.
Because the metal rod in the article is wrapped with insulation layer insulation, the main heat transfer method is only conduction (radiation heat radiation, convection convection)