| What statement is true concerning the heat transfer rates through a heat exchanger boundary wall by conduction? |
| A) Heat transfer rates are inversely proportional to the temperature gradient across the wall, and directly proportional to the area of the wall and the wall thickness. |
| B) Heat transfer rates are inversely proportional to the temperature gradient across the wall and the area of the wall, and directly proportional to the wall thickness. |
| C) Heat transfer rates are directly proportional to the temperature gradient across the wall, and inversely proportional to the area of the wall and the wall thickness. |
| D) Heat transfer rates are directly proportional to the temperature gradient across the wall and the area of the wall, and inversely proportional to the wall thickness. |
