For pipes, turbulent flow occurs when Reynolds number is
A. less than 2000
B. between 2000 and 4000
C. more than 4000
D. less than 4000
Answer: Option C
Solution (By Examveda Team)
Reynolds number is a very important dimensionless quantity in fluid mechanics. It helps us understand whether the flow of a fluid (like water in a pipe) is smooth (laminar) or chaotic (turbulent).Imagine water flowing through a pipe. If the flow is laminar, it's like perfectly ordered layers of water sliding smoothly over each other.
Turbulent flow, on the other hand, is messy! It involves swirling, mixing, and unpredictable changes in the water's velocity.
The Reynolds number (Re) is calculated using the fluid's properties (density, viscosity), its velocity, and the pipe's diameter. A higher Reynolds number means a higher velocity or a larger diameter, leading to more chaotic flow.
For flow in pipes, we use a general guideline based on the Reynolds number:
- Laminar flow: Re < 2000
- Transition region (between laminar and turbulent): 2000 < Re < 4000 (the flow can be either laminar or turbulent in this range)
- Turbulent flow: Re > 4000
Therefore, turbulent flow in pipes occurs when the Reynolds number is more than 4000.
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Comments (2)
A. 22.5 m/sec.
B. 33 m/sec.
C. 40 m/sec.
D. 90 m/sec.
A. the weight of the body
B. more than the weight of the body
C. less than the weight of the body
D. weight of the fluid displaced by the body
The difference of pressure between the inside and outside of a liquid drop is
A. $${\text{p}} = {\text{T}} \times {\text{r}}$$
B. $${\text{p}} = \frac{{\text{T}}}{{\text{r}}}$$
C. $${\text{p}} = \frac{{\text{T}}}{{2{\text{r}}}}$$
D. $${\text{p}} = \frac{{2{\text{T}}}}{{\text{r}}}$$
A. cannot be subjected to shear forces
B. always expands until it fills any container
C. has the same shear stress.at a point regardless of its motion
D. cannot remain at rest under action of any shear force
Re < 2000: Laminar flow (smooth, orderly flow).
2000 ≤ Re ≤ 4000: Transitional flow (mixed behavior).
Re > 4000: Turbulent flow (chaotic, irregular flow).
less then 2000 is correct ans