Thermal Engineering MCQ

Test your knowledge with important Thermal Engineering MCQ and their applications. These MCQs are beneficial for competitive exams too. Explore 30 + more Thermal Engineering MCQs at Bissoy

• Why is a minimum of net positive suction head (NPSH) required for a hydraulic pump?
  ক

  To prevent cavitation

  খ

  To increase discharge

  গ

  To increase suction head

  ঘ

  To increase efficiency
• Negative slip occurs in reciprocating pumps, when delivery pipe is ______
  ক

  Long and suction pipe is short and pump is running at low speed

  খ

  Long and suction pipe is short and pump is running at high speed

  গ

  Short and suction pipe is long and pump is running at low speed

  ঘ

  Short and suction pipe is long and pump is running at high speed
• Why an air vessel is used in a reciprocating pump?
  ক

  To obtain a continuous supply of water at uniform rate

  খ

  To reduce suction head

  গ

  To increase the delivery head

  ঘ

  To reduce cavitation
• When the speed of the centrifugal pump is doubled, the power required to drive the pump will be _____
  ক

  Increase 8 times

  খ

  Increase 4 times

  গ

  Double

  ঘ

  Remain the same
• Which of the following is not an advantage of centrifugal pump?
  ক

  Low initial cost

  খ

  High efficiency

  গ

  Difficult installation

  ঘ

  Easy maintenance
• Hydraulic machine convert mechanical energy into hydraulic energy by means of centrifugal force acting on the fluid ______
  ক

  Centrifugal pump

  খ

  Rotary pump

  গ

  Multiple rotor

  ঘ

  Reciprocating pump
• Dynamic pumps are also known as ______
  ক

  Positive displacement pumps

  খ

  Non-positive displacement pumps

  গ

  Reciprocating pump

  ঘ

  Rotary pump
• Which of the following is a dynamic pump?
  ক

  Centrifugal pump

  খ

  Rotary pump

  গ

  Multiple rotor

  ঘ

  Reciprocating pump
• Which of the following is a positive displacement pump?
  ক

  Centrifugal pump

  খ

  Diffuser pump

  গ

  Axial pump

  ঘ

  Reciprocating pump
• Which hydraulic machine convert mechanical energy into pressure energy?
  ক

  Pump

  খ

  Refrigerator

  গ

  Heat engine

  ঘ

  Turbine
• When system undergoes a process such that ∫dQ/T = 0 and ∆S>0, the process is ______
  ক

  Irreversible adiabatic

  খ

  Reversible adiabatic

  গ

  Isothermal

  ঘ

  Isobaric
• Which of the following statements applicable to a perfect gas will also be true for an irreversible process?
  ক

  dQ = dU + pdV

  খ

  dQ = du – pdV

  গ

  Tds = dU + pdV

  ঘ

  Tds = du – pdV
• Availability is also known as __________
  ক

  Exergy

  খ

  Ronthalpy

  গ

  Enthalpy

  ঘ

  Entropy
• The difference between idealized reversible work and actual work done by the system is called _____
  ক

  Reversibility

  খ

  Irreversibility

  গ

  Gain in available energy

  ঘ

  Decrease in unavailable energy
• The _________ has to be rejected by any cyclic heat engine is called _________
  ক

  Maximum energy, unavailable energy

  খ

  Maximum energy, available energy

  গ

  Minimum energy, available energy

  ঘ

  Minimum energy, unavailable energy
• What is the part of heat energy which cannot be converted into mechanical work which reduce system in state of equilibrium?
  ক

  Available energy

  খ

  Electrical energy

  গ

  Unavailable energy

  ঘ

  Hydraulic energy
• The _________ obtainable from a certain heat input in a cyclic heat engine is called _________
  ক

  Maximum work, unavailable energy

  খ

  Maximum work, available energy

  গ

  Minimum work, available energy

  ঘ

  Minimum work, unavailable energy
• What is the part of heat energy which is converted into mechanical work which reduce system in state of equilibrium?
  ক

  Available energy

  খ

  Electrical energy

  গ

  Unavailable energy

  ঘ

  Hydraulic energy
• Gibbs function is given by _____
  ক

  G = H – TS

  খ

  G = pV – TS

  গ

  G = U – pV

  ঘ

  G = U + pV
• What is the lowest temperature at which heat rejection can takes place?
  ক

  100°C

  খ

  0K

  গ

  273K

  ঘ

  Temperature equal to surrounding
• Availability function (∅) is given by ______
  ক

  U-p0V-T0S

  খ

  U+p0V-T0S

  গ

  –U+p0V-T0S

  ঘ

  p0V-T0S
• What is the saturation temperature at the partial pressure of water vapor in the air water vapor mixture called?
  ক

  Dry bulb temperature

  খ

  Wet bulb temperature

  গ

  Dew point temperature

  ঘ

  Saturation temperature
• The latent heat load in an auditorium is 25% of sensible heat load. What is the value of sensible heat fact?
  ক

  0.3

  খ

  0.5

  গ

  0.8

  ঘ

  1.0
• What is the relative humidity when the wet bulb depression is zero?
  ক

  100%

  খ

  60%

  গ

  40%

  ঘ

  Zero
• Which one of the following is correct according to temperature?
  ক

  Effective temperature is the index which correlates the combined effects of air dry bulb temperature, air humidity and air movement upon human comfort

  খ

  The value of effective temperature in winter and summer should be same for human comfort

  গ

  Effective temperature and wet bulb temperature are same

  ঘ

  The valve of the effective temperature should be higher in winter than in summer for comfort
• Air at 35 and 25 degree Celsius dew point temperature passes through the water shower whose temperature is maintained at 20 degree Celsius. What is the process involved?
  ক

  Cooling and humidification

  খ

  Sensible cooling

  গ

  Cooling and dehumidification

  ঘ

  Heating and humidification
• What happens when warm saturated air is cooled?
  ক

  Excess moisture condenses

  খ

  Excess moisture condenses but relative humidity remains unchanged

  গ

  Excess moisture condenses and specific humidity increases but relative humidity remains unchanged

  ঘ

  Specific humidity increases and relative humidity increases
• The performance of an evaporation condenser largely depends on ________
  ক

  Dry bulb temperature of air

  খ

  Wet bulb temperature of air

  গ

  Hot water temperature

  ঘ

  Air conditional room temperature
• During adiabatic saturation process of air, wet bulb temperature ___________
  ক

  Increases and dry bulb temperature remains constant

  খ

  Remains constant and dry bulb temperature increases

  গ

  Remains constant and dry bulb temperature decreases

  ঘ

  Decreases and dry bulb temperature remains constant
• When a stream of moist air is passed over a cold and dry cooling coil such that no condensation takes place, then the air stream will get along the line of __________
  ক

  Constant wet bulb temperature

  খ

  Constant dew point temperature

  গ

  Constant relative humidity

  ঘ

  Constant enthalpy