Match Group A with Group B

**Group-A**
P: Biot number
Q: Grashoff number
R: Prandtl number
S: Reynolds number

**Group-B**
1: Ratio of buoyancy to viscous force
2: Ratio of inertia force to viscous force
3: Ratio of momentum to thermal diffusivities
4: Ratio of internal thermal resistance to boundary layer thermal resistance

Biot number is a ratio of internal thermal resistance to boundary layer thermal resistance

Biot number is used in transient conduction heat transfer to decide if the lumped system analysis is applicable or not.

Grashof number is a ratio of buoyancy to viscous force.

Grashof's number is used in natural convection heat transfer.

Prandtl number is a ratio of momentum diffusivity to thermal diffusivity of material.

Prandtl number is a property of the material used in convection and conduction heat transfer.

Reynolds number is a ratio of inertia force to viscous force.

It is used to know the type of flow (laminar, transient, or turbulent)