Heat Transfer - Engineering

Q1:

Resistance to heat flow by conduction is proportional to (where, t & ρ are thickness & density of the material respectively and A = area normal to the direction of heat flow. )

A t

B 1/ρ

C 1/A

D all (a), (b) & (c)

ANS:D - all (a), (b) & (c)

The correct answer is: a) t The resistance to heat flow by conduction (R) is given by the formula: R=kAt​ Where:

  • t is the thickness of the material,
  • k is the thermal conductivity of the material,
  • A is the cross-sectional area normal to the direction of heat flow.
From this equation, we can see that the resistance is directly proportional to the thickness of the material (t), but not directly proportional to density (ρ) or inversely proportional to area (1/A). Therefore, the correct answer is option (a) t.