Water is flowing through a tube of inner diameter 2mm. What should be the maximum average velocity of flow of water through the tube, for which the flow will remain laminar ?
Coefficient of viscosity of water at ${25}^{\mathrm{o}}\mathrm{C} \mathrm{is} 8.90 \mathrm{x} {10}^{-4} \mathrm{N}-\mathrm{s}/{\mathrm{m}}^2$

• A

  $1.12 \mathrm{m}/\mathrm{s}$

• B

  $89 \mathrm{cm}/\mathrm{s}$

• C

  $60 \mathrm{cm}/\mathrm{s}$

• D

  $49 \mathrm{cm}/\mathrm{s}$