निम्नलिखित में से कौन सी भौतिक परिस्थिति लम्पड सिस्टम विश्लेषण (lumped system analysis) को अधिक व्यावहारिक बनाती है?

A wall of thickness L and thermal conductivity k has a steady heat flow Q through it. The temperature drop across the wall is ΔT. What is the expression for the rate of heat conduction per unit area (q)?

In one-dimensional steady-state heat conduction through a plane wall with constant thermal conductivity, the temperature distribution is: