Question

Specific heat, coefficient of viscosity, and thermal conductivity are related in the

• A. Prandtl number
• B. Reynolds number
• C. Froude number
• D. Biot number

Hint:

Match the three named properties to the defining formula of each dimensionless number listed.

Answer 1

The Correct Option is A

Each dimensionless group in heat and fluid flow is built from a fixed set of properties, so matching the three named quantities to a formula settles this directly.

1. Prandtl number: written as $Pr = c_p \mu / k$, it uses exactly specific heat, viscosity, and thermal conductivity together.
2. Reynolds number: built from density, velocity, and a length scale over viscosity, it leaves out both specific heat and conductivity.
3. Froude number: purely a ratio of inertial to gravitational effects, velocity squared over gravity and length, no thermal terms at all.
4. Biot number: uses a surface heat transfer coefficient and a length over conductivity, not viscosity or specific heat.

The Prandtl number is the only one matching all three properties, so option A is correct.