Corrosion primarily occurs due to oxidation, where a metal reacts with oxygen in the environment, forming metal oxides. This reaction is responsible for the degradation of materials like iron and steel over time.
Which polymer is commonly used for electrical insulation?
A Teflon
B Nylon
C PVC
D Polyethylene
Polyvinyl chloride (PVC) is widely used for electrical insulation because of its excellent electrical resistance, durability, and cost-effectiveness. It is commonly found in wiring and cables for various electrical applications.
Which composite material is widely used in aerospace applications for its high strength-to-weight ratio?
A Carbon fiber
B Wood
C Bronze
D Concrete
Carbon fiber composites are widely used in aerospace due to their exceptional strength-to-weight ratio. They provide high strength while being much lighter than metals, making them ideal for applications like aircraft structures.
What is the main purpose of adding antioxidants to polymers?
A To improve flexibility
B To increase strength
C To prevent degradation
D To improve electrical conductivity
Antioxidants are added to polymers to prevent oxidative degradation, which can occur when polymers are exposed to heat, light, or oxygen over time. This helps to prolong the material’s life and maintain its properties.
Which material property is most affected by exposure to UV radiation?
A Corrosion resistance
B Hardness
C Polymer degradation
D Ductility
Exposure to ultraviolet (UV) radiation can break down the molecular structure of polymers, leading to degradation. This causes materials to become brittle, discolored, and weak over time, especially in outdoor applications.
What is the primary function of a corrosion inhibitor?
A Increase hardness
B Prevent material degradation
C Enhance conductivity
D Improve flexibility
Corrosion inhibitors are chemicals used to prevent or slow down the corrosion process in metals by forming a protective layer that shields the material from harmful environmental factors like water and oxygen.
Which of these is a characteristic of thermoplastic polymers?
A Softens when heated
B High thermal resistance
C Cannot be remolded
D Cannot conduct electricity
Thermoplastic polymers soften when heated and can be reshaped multiple times without changing their chemical structure. This makes them ideal for processes like injection molding and recycling.
Which type of composite material is commonly used in the automotive industry?
A Steel
B Carbon fiber
C Glass fiber
D Aluminum
Glass fiber composites are commonly used in the automotive industry due to their high strength and low cost. These composites are lightweight, durable, and resistant to corrosion, making them ideal for car body panels and components.
Which factor primarily affects the corrosion rate of metals?
A Humidity
B Chemical exposure
C Temperature
D All of the above
The corrosion rate of metals is influenced by various factors including humidity, temperature, and exposure to chemicals like acids or salts. Higher humidity and temperature typically accelerate corrosion processes.
What is the main characteristic of a polymer’s molecular structure that affects its properties?
A Molecular weight
B Magnetic permeability
C Thermal conductivity
D Crystal structure
The molecular weight of a polymer directly impacts its properties, such as strength, viscosity, and melting point. Polymers with higher molecular weight tend to be stronger and more durable.
Which metal is commonly used for galvanizing steel to protect it from corrosion?
A Copper
B Aluminum
C Iron
D Zinc
Zinc is commonly used for galvanizing steel because it forms a protective layer that prevents rust and corrosion. The zinc coating acts as a sacrificial anode, corroding instead of the steel underneath.
Which composite material is used in the production of high-performance tennis rackets?
A Glass fiber
B Concrete
C Stainless steel
D Carbon fiber
Carbon fiber composites are used in tennis rackets because of their lightweight and high strength properties. This allows for increased racket speed and durability while maintaining a strong frame.
Which of the following is the most common cause of corrosion in marine environments?
A Oxygen
B Saltwater
C Heat
D Radiation
Saltwater is a highly corrosive environment due to the presence of chloride ions, which accelerate the corrosion of metals, especially steel and aluminum, leading to rust and material degradation over time.
Which of the following materials is known for its resistance to chemical corrosion?
A Stainless steel
B Lead
C Copper
D Cast iron
Stainless steel is highly resistant to corrosion due to the formation of a chromium oxide layer that protects the material from environmental elements like moisture, chemicals, and oxygen.
Which polymer is commonly used in making food containers due to its low permeability?
A Polypropylene
B Polyethylene
C PET (Polyethylene Terephthalate)
D Polystyrene
PET is widely used in food containers due to its low permeability to gases and moisture, helping to preserve the freshness of food. It is also durable, lightweight, and recyclable, making it an ideal material for packaging.