China Zhongwang Interview Questions and Answers

I am a graduate engineer trainee with a strong family background. My hobbies include playing guitar and my favorite subject is mechanical engineering.

• I am a graduate engineer trainee

• I come from a strong family background

• My hobbies include playing guitar

• My favorite subject is mechanical engineering

Copper is extracted from ore through several stages including crushing, grinding, and concentration.

• The ore is first crushed into small pieces

• It is then ground to a fine powder

• The powder is then concentrated using various methods such as froth flotation

• The concentrated ore is then roasted to remove any remaining impurities

• Finally, the copper is extracted using electrolysis or smelting

• The final product is usually in the

Electrorefining, electrowinning, and electroplating are all electrochemical processes used for different purposes.

• Electrorefining is used to purify metals through electrolysis, such as copper refining.

• Electrowinning is used to extract metals from their ores through electrolysis, such as zinc production.

• Electroplating is used to coat a metal object with a thin layer of another metal, such as gold plating on jewelry.

• All ...read more

Wire drawing at room temperature is cold working for both steel and tin rods.

• Wire drawing involves pulling a metal rod through a die to reduce its diameter.

• Cold working is a process where the metal is deformed at room temperature.

• Hot working is a process where the metal is deformed at high temperatures.

• Steel and tin rods can be cold worked at room temperature through wire drawing.

• Hot working is typically done at high t...read more

Aluminium is extracted from its ore bauxite by electrolysis.

• Bauxite is first purified to produce alumina

• Alumina is then dissolved in molten cryolite

• Electrolysis is carried out using carbon electrodes

• Aluminium is produced at the cathode and oxygen at the anode

RTD measures temperature using resistance while thermocouple uses voltage difference.

• RTD has higher accuracy and stability than thermocouple.

• RTD is more expensive than thermocouple.

• RTD is suitable for precise temperature measurement while thermocouple is better for high temperature measurement.

• RTD has a linear relationship between resistance and temperature while thermocouple has a non-linear relationship.

• Examples of R...read more

Correct temperature indication by RTD can be verified using multimeter.

• Check the resistance value of RTD using multimeter and compare it with the standard resistance-temperature chart.

• Ensure that the RTD is properly connected to the measuring instrument and there are no loose connections.

• Perform a calibration check periodically to ensure accurate temperature measurement.

• Use a reference thermometer to cross-check the te...read more

Yes, 0-10 V can be used in PLC as an analog input or output signal.

• PLCs typically have analog input and output modules that can handle 0-10 V signals.

• The signal can be used to measure or control variables such as temperature, pressure, or flow.

• The resolution and accuracy of the signal depend on the PLC and the analog module used.

• Some PLCs may require additional scaling or conversion of the signal to match the desired r...read more

Dry wiring refers to wiring without any external protection, while wet wiring involves the use of protective coatings or materials.

• Dry wiring is typically used in low-risk environments where there is no chance of moisture or other contaminants damaging the wiring.

• Wet wiring is used in high-risk environments where moisture or other contaminants are present, such as in chemical plants or outdoor installations.

• Examples of...read more