Question

A metal cube of side x is in steady state with its two opposite faces kept at temperatures T₁ and T₂ (T₁ > T₂). Which change will increase the total heat Q conducted in a given time?

Options

• Decreasing the cross-sectional area of the faces

• Decreasing the temperature difference (T₁ − T₂)

• Increasing the time of contact

• Increasing the distance x between the faces

Answer 1

Increasing the time of contact

Explanation:

From Q = kA(T₁ − T₂)t/x, the heat conducted is directly proportional to time t, so increasing t increases Q if all other quantities remain the same.