Question

The liquid flow is most stream lined when:

• A. liquid of high viscosity and high density flowing through a tube of small radius
• B. liquid of high viscosity and low density flowing through a tube of small radius
• C. liquid of low viscosity and low density flowing through a tube of large radius
• D. liquid of low viscosity and high density flowing through a tube of large radius

Answer 1

The correct option is B liquid of high viscosity and low density flowing through a tube of small radius

$CriticalVelocity=\frac{coefficientofviscocity\times Reynol{d}^{\prime }snumber}{Density\times Diameter}$
For a liquid having large value of coefficient of viscocity, low density and flowing through a narrow tube, the value of critical velocity may be too large to be possessed by the liquid hence, the liquid be always be in streamline flow. Therefore, the liquid flow is most stream lined when liquid of high viscosity and low density flowing through a tube of small radius.