Blue Star Mechanical Engineer Interview Questions and Answers

Diesel engines are commonly used in trains.

• Trains typically use diesel engines due to their high torque and fuel efficiency.

• Electric engines are also used in some trains, especially in urban areas.

• Steam engines were used in the past but are now rare.

• Hybrid engines that combine diesel and electric power are becoming more common.

• The type of engine used in a train depends on factors such as the distance it travels and the...read more

P,V and T,S diagrams are graphical representations of thermodynamic processes.

• P,V diagram shows the relationship between pressure and volume.

• T,S diagram shows the relationship between temperature and entropy.

• P,V and T,S diagrams are useful in analyzing thermodynamic cycles.

• P,V and T,S diagrams can be used to determine the efficiency of a heat engine.

• P,V and T,S diagrams are commonly used in the design of power plants a...read more

Adiabatic process is a thermodynamic process where no heat is exchanged with the surroundings. Hyperbolic process is a type of adiabatic process.

• Adiabatic process occurs when there is no heat transfer between the system and its surroundings

• Hyperbolic process is a type of adiabatic process where the pressure and volume of a gas are inversely proportional

• Adiabatic compression of a gas can cause an increase in temperature

• ...read more

IDU and ODU are abbreviations used in air conditioning systems. IDU stands for Indoor Unit and ODU stands for Outdoor Unit.

• IDU is the unit that is installed inside the room or building, while ODU is installed outside.

• IDU is responsible for cooling or heating the air inside the room, while ODU is responsible for dissipating the heat outside.

• IDU is connected to ODU through refrigerant pipes and electrical cables.

• Examples...read more

Enthalpy is the heat content of a system, while entropy is the measure of disorder or randomness in a system.

• Enthalpy is the sum of internal energy and the product of pressure and volume.

• Entropy is the measure of the number of ways energy can be distributed in a system.

• Heat loss in entropy occurs due to the transfer of energy from a hot object to a cold object.

• Entropy always increases in a closed system, leading to a d...read more

AC is a device that cools and dehumidifies air while cooler is a device that cools water or other liquids.

• AC is used to cool and dehumidify air in a room or building

• Cooler is used to cool water or other liquids for drinking or industrial purposes

• AC uses refrigerant to cool the air while cooler uses water or other liquids

• AC is more expensive and complex than cooler

• AC is more commonly used in residential and commercial b...read more