Thermodynamics - Mechanical Engineering (MCQ) questions and answers
Dear Readers, Welcome to Thermodynamics multiple choice questions and answers with explanation. These objective type Thermodynamics questions are very important for campus placement test, semester exams, job interviews and competitive exams like GATE, IES, PSU, NET/SET/JRF, UPSC and diploma.
Specially developed for the Mechanical Engineering freshers and professionals, these model questions are asked in the online technical test and interview of many companies.
These tutorial are also important for your viva in university exams like Anna university, Pune, VTU, UPTU, CUSAT etc.
1) The formation of scale boiler leads to
- Published on 21 Aug 15
a. decrease in efficiency of boiler
b. increase in efficiency of boiler
c. increase in heat transfer
d. decrease in maintenance of boiler
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2) What is the pH value of water permissible for boiler?
- Published on 21 Aug 15
a. 0
b. 7
c. slightly less than 7
d. slightly more than 7
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3) When the rate of evaporation of water is zero, the relative humidity of the air is
- Published on 21 Aug 15
a. 0%
b. 100%
c. 50%
d. unpredictable
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4) When,
H1 = Total heat of air entering the coil (heating or cooling)
H2 = Total heat of air leaving the coil (heating or cooling)
H3 = Total heat of air at the end of the process (humidification or dehumidification)
then, the sensible heat factor (H2 – H1) / (H3 – H1) represents the process of
- Published on 21 Aug 15
a. cooling and humidification
b. cooling and dehumidification
c. heating and humidification
d. heating and dehumidification
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5) The dew point temperature is less than the wet bulb temperature for
- Published on 21 Aug 15
a. saturated air
b. unsaturated air
c. both saturated and unsaturated air
d. none of the above
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6) At 100% relative humidity, the wet bulb temperature is
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a. lower than the dew point temperature
b. higher than the dew point temperature
c. equal to the dew point temperature
d. none of the above
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7) What is the perfect condition for dehumidification of air?
- Published on 21 Aug 15
a. air is heated above its dew point temperature
b. air is cooled up to its dew point temperature
c. air is heated below its dew point temperature
d. air is cooled below its dew point temperature
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Answer
Explanation
Related Ques
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ANSWER: air is cooled below its dew point temperature
Explanation:
No explanation is available for this question!
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8) The gas-refrigeration system is
- Published on 21 Aug 15
a. more heavy and bulky than the vapour compression cycle
b. less heavy and bulky than the vapour compression cycle
c. same in construction with the vapour compression cycle
d. none of the above
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Answer
Explanation
Related Ques
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ANSWER: less heavy and bulky than the vapour compression cycle
Explanation:
No explanation is available for this question!
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9) How is the COP of gas-refrigeration cycle compared with the COP of vapour compression cycle, for the same capacity?
- Published on 21 Aug 15
a. the COP of gas-refrigeration cycle is lower than the COP of vapour compression cycle, for the same capacity
b. the COP of gas-refrigeration cycle is higher than the COP of vapour compression cycle, for the same capacity
c. the COP of gas-refrigeration cycle is same as the COP of vapour compression cycle
d. none of the above
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Answer
Explanation
Related Ques
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ANSWER: the COP of gas-refrigeration cycle is lower than the COP of vapour compression cycle, for the same capacity
Explanation:
No explanation is available for this question!
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10) What is the relation between brake efficiency, internal efficiency and mechanical efficiency?
- Published on 21 Aug 15
a. ηInternal = ηMech * ηBrake
b. ηMech = ηInternal * ηBrake
c. ηBrake = ηInternal * ηMech
d. none of the above
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