Non-ferrous metals in plant construction MCQs With Answer

Non-ferrous metals in plant construction MCQs With Answer

Non-ferrous metals like aluminum, copper, titanium, nickel, zinc, brass and bronze play a vital role in pharmaceutical plant construction due to their corrosion resistance, thermal conductivity and low magnetic permeability. B. Pharm students must understand material selection for tanks, piping, heat exchangers and sterile equipment, plus issues such as galvanic corrosion, leaching, cleaning-chemical compatibility, surface finish and regulatory standards. These MCQs focus on properties, alloys, fabrication, hygienic design and testing relevant to pharmaceutical manufacturing to help you choose safe, durable materials and avoid contamination risks. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Which property of aluminum makes it widely used for lightweight process equipment in pharmaceutical plants?

  • High density
  • Excellent corrosion resistance and low density
  • Magnetic permeability
  • High alloying with lead

Correct Answer: Excellent corrosion resistance and low density

Q2. Which non-ferrous metal is known for natural antimicrobial properties useful in touch surfaces?

  • Aluminum
  • Copper
  • Zinc
  • Bronze

Correct Answer: Copper

Q3. Which alloy combination typically defines brass?

  • Copper and zinc
  • Copper and tin
  • Aluminum and magnesium
  • Nickel and chromium

Correct Answer: Copper and zinc

Q4. What is the primary corrosion concern for non-ferrous metals in chloride-containing cleaning solutions?

  • General uniform corrosion only
  • Chloride-induced pitting and stress corrosion
  • Galvanic protection improvement
  • Improved passivation

Correct Answer: Chloride-induced pitting and stress corrosion

Q5. Which non-ferrous metal is most problematic due to toxicity and must be avoided in pharma contact surfaces?

  • Lead
  • Aluminum
  • Copper
  • Titanium

Correct Answer: Lead

Q6. For high-temperature exchangers needing corrosion resistance and strength, which metal is often selected?

  • Pure copper
  • Titanium
  • Low-grade zinc
  • Pure lead

Correct Answer: Titanium

Q7. Which of the following is a common surface treatment to improve aluminum corrosion resistance?

  • Anodizing
  • Carburizing
  • Galvanizing with lead
  • Nitriding

Correct Answer: Anodizing

Q8. What does PMI (Positive Material Identification) test detect in non-ferrous components?

  • Surface roughness only
  • Bulk chemical composition and alloy confirmation
  • Magnetic permeability
  • Fatigue life

Correct Answer: Bulk chemical composition and alloy confirmation

Q9. Which non-ferrous metal has excellent electrical and thermal conductivity often used in heat exchangers?

  • Nickel
  • Copper
  • Lead
  • Brass

Correct Answer: Copper

Q10. Galvanic corrosion occurs when two different metals are electrically connected in an electrolyte. Which pairing increases galvanic risk?

  • Titanium with titanium
  • Aluminum connected to copper
  • Copper connected to copper
  • Brass connected to bronze

Correct Answer: Aluminum connected to copper

Q11. In pharmaceutical piping, why is surface finish (polish) important for non-ferrous metals?

  • It increases porosity
  • It reduces bacterial adhesion and facilitates cleaning
  • It increases galvanic corrosion
  • It increases chemical leaching

Correct Answer: It reduces bacterial adhesion and facilitates cleaning

Q12. Which non-ferrous alloy is commonly used for sanitary fittings due to machinability and moderate corrosion resistance?

  • Bronze
  • Bronze with lead inclusions
  • Brass (dezincification-resistant when suited)
  • Pure zinc

Correct Answer: Brass (dezincification-resistant when suited)

Q13. Dezincification is a corrosion mechanism affecting which material?

  • Aluminum alloys
  • Brass
  • Titanium alloys
  • Nickel-based superalloys

Correct Answer: Brass

Q14. Which cleaning agent class can aggressively attack aluminum and certain non-ferrous alloys?

  • Neutral buffered solutions
  • Strong caustic (alkaline) solutions
  • Distilled water
  • Alcohol-based sanitizers only

Correct Answer: Strong caustic (alkaline) solutions

Q15. What advantage do non-ferrous metals offer compared to ferrous metals in pharmaceutical plants?

  • Higher magnetic susceptibility
  • Better corrosion resistance and non-magnetic properties
  • Cheaper in all applications
  • Always higher strength

Correct Answer: Better corrosion resistance and non-magnetic properties

Q16. Which test method assesses surface cleanliness and potential contamination from metal leaching?

  • Hardness testing
  • ICP-OES or ICP-MS chemical analysis
  • Ultrasonic thickness only
  • Visual inspection only

Correct Answer: ICP-OES or ICP-MS chemical analysis

Q17. Which non-ferrous metal forms a stable passive oxide layer giving excellent corrosion resistance in many environments?

  • Aluminum
  • Lead
  • Pure copper
  • Brass

Correct Answer: Aluminum

Q18. Which joining method is preferred for joining dissimilar non-ferrous metals without melting the base metals?

  • Fusion welding
  • Brazing
  • Cold forging
  • Riveting only

Correct Answer: Brazing

Q19. Which non-ferrous metal is most suitable for highly corrosive seawater applications and some pharmaceutical processes?

  • Pure zinc
  • Titanium
  • Lead
  • Low-grade copper

Correct Answer: Titanium

Q20. Which alloying element is commonly added to copper to improve strength and corrosion resistance in heat exchanger tubes?

  • Lead
  • Tin (forming bronze)
  • Gold
  • Magnesium

Correct Answer: Tin (forming bronze)

Q21. What is a major concern when using aluminum in contact with acidic pharmaceutical solutions?

  • Improved passivation
  • Acid-induced corrosion and localized attack
  • Formation of non-reactive film increasing safety
  • Decreased thermal conductivity

Correct Answer: Acid-induced corrosion and localized attack

Q22. Which standard is commonly referenced for material and design of pressure vessels used in pharma plants?

  • ASTM only for paints
  • ASME Boiler and Pressure Vessel Code
  • ISO food packaging only
  • USP monographs unrelated to materials

Correct Answer: ASME Boiler and Pressure Vessel Code

Q23. Which non-destructive test is commonly used to detect surface cracks in non-ferrous welds?

  • Magnetic particle testing
  • Dye penetrant testing
  • Radiography only for ferrous metals
  • Hardness testing only

Correct Answer: Dye penetrant testing

Q24. For sterile pharmaceutical tanks, which property of titanium makes it favorable despite higher cost?

  • High solubility in most APIs
  • Excellent corrosion resistance and biocompatibility
  • High magnetic response
  • Low strength

Correct Answer: Excellent corrosion resistance and biocompatibility

Q25. Which phenomenon can cause selective removal of zinc from brass, weakening components?

  • Passivation
  • Dezincification
  • Intergranular nitriding
  • Annealing

Correct Answer: Dezincification

Q26. Which non-ferrous metal is susceptible to hydrogen embrittlement when exposed to certain process environments?

  • Gold
  • Titanium and some high-strength alloys
  • Zinc in all forms
  • Pure copper is immune

Correct Answer: Titanium and some high-strength alloys

Q27. Which parameter is critical to specify for pharma-grade copper alloys to minimize contamination?

  • Porosity only
  • Lead content and overall chemical composition limits
  • Color shade
  • Magnetic coercivity

Correct Answer: Lead content and overall chemical composition limits

Q28. Which surface treatment for stainless steel is analogous to anodizing for aluminum to improve cleanliness?

  • Electropolishing
  • Carburizing
  • Hot-dip galvanizing
  • Flame hardening

Correct Answer: Electropolishing

Q29. Which metal property directly affects thermal sterilization efficiency in heat exchangers?

  • Thermal conductivity
  • Electrical resistivity
  • Magnetic permeability
  • Optical reflectivity

Correct Answer: Thermal conductivity

Q30. In selecting materials for clean-in-place (CIP) systems, which factor is most important?

  • Compatibility with CIP chemicals and temperatures
  • Color match to piping
  • Ability to corrode rapidly
  • High porosity

Correct Answer: Compatibility with CIP chemicals and temperatures

Q31. Which non-ferrous metal frequently requires passivation to remove free iron contamination after fabrication?

  • Lead
  • Aluminum
  • Copper-based alloys and titanium surfaces after machining
  • Pure gold

Correct Answer: Copper-based alloys and titanium surfaces after machining

Q32. Which test identifies localized corrosion susceptibility like pitting in non-ferrous alloys?

  • Potentiodynamic polarization (electrochemical testing)
  • Tensile testing only
  • Visual color assessment
  • Thermal expansion measurement

Correct Answer: Potentiodynamic polarization (electrochemical testing)

Q33. Which non-ferrous alloying element improves strength and corrosion resistance in aluminum alloys used for structural components?

  • Magnesium
  • Mercury
  • Lead
  • Gold

Correct Answer: Magnesium

Q34. For pharmaceutical tanks requiring non-magnetic behavior and good formability, which metal is often chosen?

  • Low-carbon steel
  • Aluminum
  • Wrought iron
  • Cast iron

Correct Answer: Aluminum

Q35. Which of the following affects the rate of galvanic corrosion between two metals?

  • Potential difference between metals and area ratio exposed
  • Only the color of metals
  • Distance between plants
  • Time of day

Correct Answer: Potential difference between metals and area ratio exposed

Q36. Why is nickel often used as an alloying element in harsh pharmaceutical environments?

  • It lowers corrosion resistance
  • It improves toughness, corrosion resistance and high-temperature strength
  • It increases toxicity drastically
  • It makes metals magnetic

Correct Answer: It improves toughness, corrosion resistance and high-temperature strength

Q37. Which inspection is suitable to verify weld integrity in non-ferrous pipework for sterile transfer?

  • Pressure/leak testing and dye-penetrant on welds
  • Only visual inspection is acceptable
  • Thermal imaging for color match
  • Smell test

Correct Answer: Pressure/leak testing and dye-penetrant on welds

Q38. Which non-ferrous metal commonly forms protective cuprous oxide films but can leach ions under acidic conditions?

  • Aluminum
  • Copper
  • Lead
  • Magnesium

Correct Answer: Copper

Q39. What is a key reason to avoid direct contact between aluminum and stainless steel in an electrolyte?

  • They form a stable alloy
  • Risk of galvanic corrosion of aluminum when paired with nobler stainless steel
  • They always weld together perfectly
  • They become non-reactive

Correct Answer: Risk of galvanic corrosion of aluminum when paired with nobler stainless steel

Q40. Which property defines resistance to permanent deformation and is important for load-bearing non-ferrous components?

  • Hardness and yield strength
  • Electrical conductivity
  • Optical transparency
  • Magnetic susceptibility

Correct Answer: Hardness and yield strength

Q41. Which metal is commonly used for sacrificial anodes in cathodic protection but is not typically used for pharma contact parts?

  • Zinc
  • Titanium
  • Stainless steel
  • Copper

Correct Answer: Zinc

Q42. What machining concern is notable for non-ferrous metals in pharma component fabrication?

  • Non-ferrous metals cannot be machined
  • Tendency to gall or smear and require optimized tooling and speeds
  • They always produce brittle chips
  • Machining always removes passivation irreversibly

Correct Answer: Tendency to gall or smear and require optimized tooling and speeds

Q43. Which non-ferrous alloy is often avoided for direct contact with acidic APIs due to risk of ion contamination?

  • High-purity titanium
  • Unlined brass
  • EP-grade PTFE (note: not metal)
  • Gold-plated surfaces

Correct Answer: Unlined brass

Q44. In pharmaceutical plant design, what advantage do non-magnetic non-ferrous metals provide?

  • Interference with magnetic sensors and MRI safety
  • Compatibility with magnetic separation equipment and non-interference with instruments
  • Always higher corrosion
  • Lower cleanliness

Correct Answer: Compatibility with magnetic separation equipment and non-interference with instruments

Q45. Which material test helps ensure that non-ferrous piping meets hygienic smoothness requirements?

  • Surface roughness (Ra) measurement
  • Magnetic permeability test only
  • Microhardness only
  • Colorimetry

Correct Answer: Surface roughness (Ra) measurement

Q46. Which alloy is known for excellent corrosion resistance in chloride media, sometimes outperforming stainless steels?

  • Brass with high zinc
  • Titanium and some nickel-based alloys
  • Pure lead
  • Low-grade aluminum

Correct Answer: Titanium and some nickel-based alloys

Q47. What is an important consideration when electropolishing non-ferrous alloy surfaces used in sterile environments?

  • Electropolishing roughens the surface
  • It reduces surface roughness and removes embedded contaminants
  • It increases leachable ions
  • It always adds a thick coating

Correct Answer: It reduces surface roughness and removes embedded contaminants

Q48. Which metal is selected when very low density and reasonable corrosion resistance are priorities for portable pharma equipment?

  • Lead
  • Aluminum
  • Nickel
  • Copper

Correct Answer: Aluminum

Q49. Which factor must be controlled to prevent chloride stress corrosion cracking in copper-nickel alloys?

  • Maintain high chloride concentration
  • Control tensile stresses, temperature and chloride exposure
  • Always add lead to the alloy
  • Ensure frequent mechanical abrasion

Correct Answer: Control tensile stresses, temperature and chloride exposure

Q50. When specifying a non-ferrous material for pharmaceutical contact, which combined criteria is most critical?

  • Color and weight only
  • Mechanical properties, corrosion resistance, chemical compatibility and regulatory compliance
  • Availability in bright finish only
  • Ability to corrode quickly

Correct Answer: Mechanical properties, corrosion resistance, chemical compatibility and regulatory compliance

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