10+ Polmon Instruments Interview Questions and Answers

Data type is a classification of data items based on the type of value they hold. C programming has various data types.

• Data type determines the type of data that can be stored in a variable

• C programming has basic data types like int, float, char, double, etc.

• C programming also has derived data types like arrays, pointers, structures, unions, etc.

Unit operation refers to a single step in a process, while unit process involves a series of steps to achieve a specific goal.

• Unit operation is a single step in a process, such as filtration or distillation.

• Unit process involves a series of unit operations to achieve a specific goal, such as producing a certain chemical compound.

• Unit process is a more complex and comprehensive process than unit operation.

• Unit operation is often used as a building block for unit process.

• Exampl...read more

The name of AC to DC converter IC is dependent on the specific IC being used.

• There are many different AC to DC converter ICs available on the market

• Some popular AC to DC converter ICs include the LM7805, LM7812, and LM317

• The specific IC chosen will depend on the requirements of the circuit being designed

There are several types of heat exchangers including shell and tube, plate and frame, and air-cooled.

• Shell and tube heat exchangers are the most common type and consist of a shell with tubes running through it.

• Plate and frame heat exchangers use thin plates to transfer heat between fluids.

• Air-cooled heat exchangers use air as the cooling medium instead of water or other liquids.

• Other types include double pipe, spiral, and finned tube heat exchangers.

The OSI model has 7 layers that define how data is transmitted over a network.

• The layers are: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

• Each layer has a specific function and communicates with the layers above and below it.

• For example, the Physical layer deals with the physical transmission of data, while the Application layer deals with user interfaces and application-level protocols.

• The OSI model is a conceptual model and is not always ...read more

An array in C is a collection of elements of the same data type stored in contiguous memory locations.

• Arrays are declared using square brackets []

• Elements in an array can be accessed using their index number

• Arrays can be initialized during declaration or later using a loop

• Example: int arr[5] = {1, 2, 3, 4, 5};

• Example: for(int i=0; i<5; i++) { arr[i] = i+1; }

A multiplexer is a device that selects one of several input signals and forwards the selected input into a single line.

• Multiplexers are used in digital circuits to reduce the number of input/output lines required to transmit data.

• They are also used in communication systems to combine multiple signals into a single transmission line.

• Multiplexers can be implemented using logic gates or integrated circuits.

• Examples of multiplexers include 2-to-1, 4-to-1, and 8-to-1 multiplexers.

Carnot's cycle is a theoretical thermodynamic cycle that describes the most efficient heat engine possible.

• It consists of four reversible processes: isothermal expansion, adiabatic expansion, isothermal compression, and adiabatic compression.

• It operates between two heat reservoirs at different temperatures.

• The efficiency of the cycle is given by the ratio of the temperature difference between the two reservoirs to the temperature of the hotter reservoir.

• It is a theoretical id...read more

Distillation is a process of separating components of a mixture based on their boiling points. There are several types of distillation.

• Simple distillation: used for separating components with a large difference in boiling points

• Fractional distillation: used for separating components with closer boiling points

• Steam distillation: used for separating heat-sensitive compounds

• Vacuum distillation: used for separating components with high boiling points

• Azeotropic distillation: used ...read more

Distillation is a process of separating components of a mixture based on their boiling points.

• The mixture is heated to vaporize the component with the lowest boiling point

• The vapor is then condensed and collected as a separate liquid

• This process is repeated for each component with a higher boiling point

• Examples include the production of ethanol from fermented grains and the purification of water

Refrigeration cycle is a process of removing heat from a space or substance and transferring it to another space or substance.

• The cycle consists of four main components: compressor, condenser, expansion valve, and evaporator.

• The refrigerant is compressed by the compressor and then condensed in the condenser, releasing heat.

• The high-pressure liquid refrigerant then passes through the expansion valve, where it expands and becomes a low-pressure liquid.

• The low-pressure liquid re...read more

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

• Enthalpy is a thermodynamic property that describes the amount of heat released or absorbed during a process.

• Entropy is a measure of the degree of randomness or disorder in a system.

• Enthalpy and entropy are related through the Gibbs free energy equation.

• Enthalpy is usually denoted by the symbol H while entropy is denoted by S.

• An example of enthalpy is the heat released ...read more

Vapor pressure is the pressure exerted by the vapor of a substance in equilibrium with its liquid or solid phase.

• Vapor pressure increases with temperature

• Substances with high vapor pressure evaporate easily

• Vapor pressure is used in distillation and evaporation processes

• Vapor pressure can be measured using a variety of techniques