MCQOPTIONS
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MCQOPTIONS
This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Computational Fluid Dynamics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The velocity at cross-stream of a turbulent wake is calculated using the formula\(\frac{U_{max}-U}{U_{max}-U_{min}}=b(\frac{y}{b})\) Note:Umax→ Maximum velocity at a particular cross-sectionUmin→ Minimum velocity at a particular cross-sectiony → Distance in the cross-stream direction from the centre line at the cross sectionb → Cross-stream half widthU → Velocity at the distance ‘y’The minimum velocity here corresponds to _____________ |
| A. | Velocities at the edges |
| B. | Velocities just downstream of the object |
| C. | Velocities of the surrounding free stream |
| D. | Velocities at the centreline |
| Answer» C. Velocities of the surrounding free stream | |
| 2. |
The mean velocity gradient is zero at the centreline for ___________ |
| A. | jets |
| B. | mixing flows |
| C. | mixing flows and wakes |
| D. | jets and wakes |
| Answer» E. | |
| 3. |
Which of these is correct for turbulent jets?Note:Umax → Maximum velocity at a particular cross-sectionUmin → Minimum velocity at a particular cross-sectiony → Distance in the cross-stream direction from the centre line at the cross sectionb → Cross-stream half widthU → Velocity at the distance ‘y’. |
| A. | \(\frac{U}{U_{max}-U_{min}}=a(\frac{y}{b})\) |
| B. | \(\frac{U_{max}-U}{U_{max}-U_{min}}=b(\frac{y}{b})\) |
| C. | \(\frac{U-U_{min}}{U_{max}-U_{min}}=c(\frac{y}{b})\) |
| D. | \(\frac{U}{U_{max}}=d(\frac{y}{b})\) |
| Answer» E. | |
| 4. |
If y is the distance in the cross-stream direction from the centre line at a particular cross-section b → Cross-stream half width. The mean velocity gradients and all the velocity fluctuations become zero when the value \(\frac{y}{b}\) ___________ |
| A. | goes above unity |
| B. | goes below unity |
| C. | goes above zero |
| D. | goes below zero |
| Answer» B. goes below unity | |
| 5. |
Which of these is correct for mixing layer turbulent flows?Note:Umax → Maximum velocity at a particular cross-sectionUmin → Minimum velocity at a particular cross-sectiony → Distance in the cross-stream direction from the centre line at the cross sectionb → Cross-stream half widthU → Velocity at the distance ‘y’. |
| A. | \(\frac{U}{U_{max}-U_{min}}=a(\frac{y}{b})\) |
| B. | \(\frac{U_{max}-U}{U_{max}-U_{min}}=b(\frac{y}{b})\) |
| C. | \(\frac{U}{U_{max}}=c(\frac{y}{b})\) |
| D. | \(\frac{U-U_{min}}{U_{max}-U_{min}}=d(\frac{y}{b})\) |
| Answer» E. | |
| 6. |
Turbulent entrainment leads to ___________ |
| A. | Increase in the magnitude of the velocity gradients in the flow direction |
| B. | Increase in the magnitude of the velocity gradients in the cross-stream direction |
| C. | Decrease in the magnitude of the velocity gradients in the flow direction |
| D. | Decrease in the magnitude of the velocity gradients in the cross-stream direction |
| Answer» D. Decrease in the magnitude of the velocity gradients in the cross-stream direction | |
| 7. |
The velocity of a free turbulent flow at any particular distance in the cross-stream direction is a function of ___________ |
| A. | The ratio of the distance in the cross-stream direction from the centreline and half-width at that cross section |
| B. | The source velocity |
| C. | The cross-stream velocity of the source |
| D. | The velocity in the flow direction of the source |
| Answer» B. The source velocity | |
| 8. |
A turbulent jet is formed because ___________ |
| A. | A region of high-speed flow is surrounded by a stationary fluid |
| B. | An object disturbs the flow |
| C. | Interaction between an object and a fast moving fluid |
| D. | Interaction of fast and slow moving fluids |
| Answer» B. An object disturbs the flow | |
| 9. |
Which of these terms represent the burst of turbulent activity to the outer region? |
| A. | Crisis |
| B. | Intermittency |
| C. | Turbulent burst |
| D. | Turbulent jumps |
| Answer» C. Turbulent burst | |
| 10. |
The process which is responsible for spreading of turbulent flows in the flow direction is __________ |
| A. | Pluming |
| B. | Entrainment |
| C. | Turbulent mixing |
| D. | Turbulent generation |
| Answer» C. Turbulent mixing | |