When a body is placed on a Smooth horizontal surface, then the Reaction force is equal to

When a body is placed on a smooth horizontal surface

We get frictional force f = 0

Then reaction force $\text{R\hspace{0.17em}=\hspace{0.17em}}\sqrt{{\text{N}}^{\text{2}}+{\text{f}}^{\text{2}}}$

$\Rightarrow \text{R}=\text{N}$

So we get reaction force is equal to normal reaction