Consider a steady, laminar, and incompressible flow over a flat plate, as shown in the figure. With freestream velocity $U_{\infty}$ and kinematic viscosity $v_{1}$, the boundary layer thickness at a distance $x_{1}$ from the leading edge is $\delta_{1}$. If the kinematic viscosity of the fluid is increased by a factor of four $\left(v_{2}=4 v_{1}\right)$, the boundary layer thickness $\left(\delta_{2}\right)$ at $x_{1}$ with same $U_{\infty}$ will be equal to
- $\dfrac{\delta_{1}}{2}$
- $\delta_{1}$
- $2 \delta_{1}$
- $4 \delta_{1}$
