Reynold's Number

Q.

The correct formula of critical velocity $\left(V_c\right)$ is________

Q. The ratio of inertial forces to viscous forces is known as

1. Coefficient of viscosity
2. Reynolds number
3. Fluid compressibility
4. None of these

Q.

Water flows at a speed of 6 cm s^-1 through a tube of radius 1 cm. Coefficient of viscosity of water at room temperature is 0.01 poise. Calculate the Reynolds number. Is it a steady flow?

1. 60, yes

2. 60, no

3. 120, yes

4. 120, no

Q. Calculate Reynold's number if a fluid having a viscosity of $0.25{\text{N.s/m}}^2$ and density of $800{\text{kg/m}}^3$ flows through a pipe of radius $10\text{mm}$ with a velocity of $2\text{m/s}$.

1. $120$
2. $128$
3. $132$
4. $114$

Q. Calculate Reynold's number if a fluid having a viscosity of $0.25{\text{N.s/m}}^2$ and density of $800{\text{kg/m}}^3$ flows through a pipe of radius $10\text{mm}$ with a velocity of $2\text{m/s}$.

1. $120$
2. $128$
3. $132$
4. $114$

Q. Calculate Reynold’s number, if a fluid having a viscosity of $0.4{\text{Ns/m}}^2$ and density of $900{\text{kg/m}}^3$ flows through a pipe of length $20\text{mm}$ with a velocity of $2.5\text{m/s}$.

1. $112.5$
2. $130$
3. $121.5$
4. $100$

Q. Water flows at a speed of $16\text{cm/s}$ through a tube of radius $10\text{cm}$. Co-efficient of viscosity of water at room temperature is $0.01\text{Pa-s}$. Then, find the Reynolds number.

1. $3000$
2. $2800$
3. $3200$
4. $3400$

Q. If a fluid having viscosity $0.6{\text{Ns/m}}^2$ and density of $900{\text{kg/m}}^3$, flows through a pipe of diameter $40\text{mm}$, then find the maximum velocity of fluid (in $\text{m/s}$) inside the pipe for laminar flow. (Critical Reynold's number $=2100$)

1. $35$
2. $90$
3. $46.6$
4. $31.5$

Q. Low value of Reynolds Number of a flow signify

1. Laminar flow
2. Turbulent flow
3. Natural flow
4. Non-uniform flow

Q. Calculate Reynolds number, if a fluid having viscosity of $0.5{\text{Ns/m}}^2$ and density of $450{\text{kg/m}}^3$, flows through a pipe of $20\text{mm}$ diameter with an average velocity of $2.5\text{m/s}$.

1. $225$
2. $90$
3. $45$
4. $144$