MCQOPTIONS
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MCQOPTIONS
This section includes 9 Mcqs, each offering curated multiple-choice questions to sharpen your Thermal Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The following data refers to a steam condenser – Inlet temperature of cooling water = 36°C Absolute pressure inside the condenser = 0.12 bar efficiency = 78% Determine the outlet temperature of cooling water. |
| A. | 42.37°C |
| B. | 39.12°C |
| C. | 46.49°C |
| D. | 35.21°C |
| Answer» D. 35.21°C | |
| 2. |
In a condenser, the temperature of steam entering in the condenser is observed to be 30°C. The condenser vacuum is recorded to be 670 mm of Hg. If the barometer reading is 760 mm of Hg, determine the vacuum efficiency. |
| A. | 92.01% |
| B. | 84.25% |
| C. | 31.65% |
| D. | 67.51% |
| Answer» B. 84.25% | |
| 3. |
The inlet and outlet temperatures of cooling water to a certain condenser are recorded to be 30°C and 40°C respectively. If the absolute pressure in the condenser is given to be 0.11 bar, determine efficiency. |
| A. | 45.21% |
| B. | 75.65% |
| C. | 95.32% |
| D. | 56.46% |
| Answer» E. | |
| 4. |
Which of the following is the correct expression for calculating condenser efficiency? |
| A. | \(\frac{Rise \, in \, temperature \, of \, cooling \, water}{Temp. \, corresponding \, to \, vacuum \, in \, the \, condenser-Inlet \, temperature \, of \, cooling \, water} \) |
| B. | \(\frac{Rise \, in \, temperature \, of \, cooling \, water}{Inlet \, temperature \, of \, cooling \, water- Temp. \, corresponding \, to \, vacuum \, in \, the \, condenser} \) |
| C. | \(\frac{Inlet \, temperature \, of \, cooling \, water-Temp. \, corresponding \, to \, vacuum \, in \, the \, condenser}{Rise \, in \, temperature \, of \, cooling \, water} \) |
| D. | \(\frac{Temp. \, corresponding \, to \, vacuum \, in \, the \, condenser-Inlet \, temperature \, of \, cooling \, water}{Rise \, in \, temperature \, of \, cooling \, water} \) |
| Answer» B. \(\frac{Rise \, in \, temperature \, of \, cooling \, water}{Inlet \, temperature \, of \, cooling \, water- Temp. \, corresponding \, to \, vacuum \, in \, the \, condenser} \) | |
| 5. |
Which of the following is the correct definition of condenser efficiency? |
| A. | It is the ratio of the difference between the outlet and the inlet temperatures of cooling water to the difference between the temperature corresponding to the vacuum in the condenser and inlet temperature of cooling water |
| B. | It is the ratio of the difference between the temperature corresponding to the vacuum in the condenser and inlet temperature of cooling water to the difference between the inlet and outlet temperature of cooling water |
| C. | It is the ratio of the difference between the atmospheric pressure and the absolute pressure inside the condenser to the difference between the atmospheric pressure and the absolute partial pressure of the steam |
| D. | It is the ratio of the difference between the actual pressure inside the condenser and the partial pressure of the steam to the atmospheric pressure |
| Answer» B. It is the ratio of the difference between the temperature corresponding to the vacuum in the condenser and inlet temperature of cooling water to the difference between the inlet and outlet temperature of cooling water | |
| 6. |
Which of the following expressions is the correct one for calculating the vacuum efficiency of a condenser? |
| A. | \(\frac{Actual \, vacuum}{Absolute \, pressure \, of \, steam-Barometer \, Pressure} \) |
| B. | \(\frac{Actual \, vacuum}{Barometer \, Pressure-Absolute \, pressure \, of \, steam} \) |
| C. | \(\frac{Barometer \, Pressure-Absolute \, pressure \, of \, steam}{Actual \, vacuum} \) |
| D. | \(\frac{Absolute \, pressure \, of \, steam-Barometer \, Pressure}{Actual \, vacuum} \) |
| Answer» C. \(\frac{Barometer \, Pressure-Absolute \, pressure \, of \, steam}{Actual \, vacuum} \) | |
| 7. |
Which of the following is the correct definition of vacuum efficiency? |
| A. | It is the ratio of actual vacuum to atmospheric pressure |
| B. | It is the ratio of atmospheric pressure to actual vacuum |
| C. | It is the ratio of maximum obtainable vacuum to actual vacuum |
| D. | It is the ratio of actual vacuum to maximum obtainable vacuum |
| Answer» E. | |
| 8. |
What instrument is used to measure vacuum in the condensers. |
| A. | Thermometer |
| B. | Vacuum gauge |
| C. | Barometer |
| D. | Pressure transducer |
| Answer» C. Barometer | |
| 9. |
What type of pump can be used for obtaining maximum vacuum in condensers? |
| A. | Air pump |
| B. | Centrifugal pump |
| C. | Steam pump |
| D. | Gear pump |
| Answer» B. Centrifugal pump | |