MCQOPTIONS
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MCQOPTIONS
This section includes 9 Mcqs, each offering curated multiple-choice questions to sharpen your Fluid Mechanics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
One feels heavier in a lift when the lift |
| A. | Is going down steadily |
| B. | Just begins to go up |
| C. | Is moving up steadily |
| D. | Descends freely |
| Answer» C. Is moving up steadily | |
| 2. |
An automobile moving at a velocity of 40 km/hr is experiencing a wind resistance of 2 kN. If the automobile is moving at a velocity of 50 km/hr, the power required to overcome the wind resistance is |
| A. | 43.1 kW |
| B. | 3.125 W |
| C. | 2.5 kW |
| D. | 27.77 kW |
| Answer» B. 3.125 W | |
| 3. |
A man, 65 kg, descends to the ground with the help of a parachute, 18 kg. The parachute is hemispherical in shape, 2 m diameter. Density of air can be taken as 0.00125 g/cm3 and its kinematic viscosity as 0.15 stoke. What is the terminal velocity of the parachute?(Take OD – 1.5 and g – 1000 cm/sec2) |
| A. | 16.6 m/sec |
| B. | 15.8 m/sec |
| C. | 15.0 m/sec |
| D. | 14.1 m/sec |
| Answer» B. 15.8 m/sec | |
| 4. |
A vertical air stream flowing at a velocity of 100 m/s supports a ball of 60 mm in diameter. Taking the density of air as 1.2 kg/m3 and kinematic viscosity as 1.6 stokes, the weight of the ball that is supported is (if coefficient of drag CD = 0.8) |
| A. | 20.2 N |
| B. | 13.5 N |
| C. | 30.1 N |
| D. | 25.2 N |
| Answer» C. 30.1 N | |
| 5. |
In calculating the drag force using CD the are used is |
| A. | always the frontal area |
| B. | the planform area when the body is flat like an airfoil |
| C. | the planform area when the body is bluff like a sphere |
| D. | always the planform area |
| E. | Lateral area |
| Answer» C. the planform area when the body is bluff like a sphere | |
| 6. |
An airfoil of surface area 0.1 m2 is tested for lift L m a wind tunnel. (Conditions can be considered as incompressible flow.) At an angle of attack of 5°, with standard air of density 1.22 kg/m3, at a speed of 30 m/sec, the lift is measured to be 3.2 kgf. What is the lift coefficient? For a prototype wing of area 10 m2, what is the approximate lift at an air speed of 160 kmph at the same angle of attack of 5°? |
| A. | 0.572 and 700 kgf |
| B. | 0.603 and 700 kgf |
| C. | 0.572 and 570 kef |
| D. | 0.603 and 570 kef |
| Answer» B. 0.603 and 700 kgf | |
| 7. |
Consider an incompressible laminar boundary layer flow over a flat plate of length L, aligned with the direction of an incoming uniform free stream. If F is the ratio of the drag force on the front half of the plate to the drag force on the rear half, then |
| A. | F < ½ |
| B. | F = ½ |
| C. | F = 1 |
| D. | F > 1 |
| Answer» E. | |
| 8. |
ln which of the following the friction drag is generally larger than pressure drag? |
| A. | a circular disc or plate held normal to flow |
| B. | a sphere |
| C. | a cylinder |
| D. | an airfoil |
| Answer» E. | |
| 9. |
An airfoil is a streamlined body as shown in the figure below. Because of the streamlining of the body, the separation occurs only at the extreme rear of the body, resulting in |
| A. | A very high-pressure drag |
| B. | A small wake and consequently small pressure drag |
| C. | A moderate pressure drag |
| D. | No pressure drag |
| Answer» C. A moderate pressure drag | |