ANS:B - 0.6 to 120

The Calburn analogy relates the heat transfer coefficient to the mass transfer coefficient in a system. It is often applied in cases where both heat transfer and mass transfer occur simultaneously, such as in evaporative cooling or condensation processes. The Prandtl number (𝑃𝑟Pr) is a dimensionless number that represents the ratio of momentum diffusivity to thermal diffusivity. It is defined as: 𝑃𝑟=Momentum diffusivityThermal diffusivity=𝜇⋅𝑐𝑝𝑘Pr=Thermal diffusivityMomentum diffusivity​=kμ⋅cp​​ where:

• 𝜇μ is the dynamic viscosity,
• 𝑐𝑝cp​ is the specific heat at constant pressure,
• 𝑘k is the thermal conductivity.

The range of Prandtl numbers over which the Calburn analogy is typically applicable depends on the specific conditions of the system. However, generally, it is most commonly applied in the range of 0.6 to 120. So, the correct range for the applicability of the Calburn analogy is: 0.6 to 1200.6to120