1. What process occurs when a molten metal transforms into a solid state?
a) Melting
b) Solidification
c) Sublimation
d) Evaporation
Answer: b) Solidification
Explanation: Solidification is the process wherein a molten metal transforms into a solid state upon cooling. This process involves the arrangement of atoms or ions into a crystalline structure.
2. Which term describes the orderly arrangement of atoms or ions in a crystalline solid?
a) Amorphous
b) Crystallography
c) Metastability
d) Creep
Answer: b) Crystallography
Explanation: Crystallography is the study of the arrangement of atoms or ions in crystalline solids. It helps in understanding the crystal structure and its properties.
3. What type of bond is typically found in metallic substances?
a) Ionic bond
b) Covalent bond
c) Metallic bond
d) Hydrogen bond
Answer: c) Metallic bond
Explanation: Metallic substances are characterized by metallic bonding, where positively charged metal ions are surrounded by a sea of delocalized electrons, allowing for the free movement of electrons within the structure.
4. Which property refers to a material’s ability to return to its original shape after deformation?
a) Strength
b) Hardness
c) Elasticity
d) Malleability
Answer: c) Elasticity
Explanation: Elasticity is the property of a material to return to its original shape and size after the removal of stress or deformation.
5. Which term describes a material’s ability to withstand permanent deformation under applied stress?
a) Strength
b) Hardness
c) Elasticity
d) Plasticity
Answer: d) Plasticity
Explanation: Plasticity is the ability of a material to undergo permanent deformation without rupturing when subjected to applied stress beyond its elastic limit.
6. What property allows a material to be hammered or rolled into thin sheets without breaking?
a) Strength
b) Hardness
c) Malleability
d) Ductility
Answer: c) Malleability
Explanation: Malleability is the property of a material that enables it to be hammered or rolled into thin sheets without fracturing.
7. Which term refers to the gradual deformation of a material under constant stress over time?
a) Creep
b) Fatigue
c) Elasticity
d) Plasticity
Answer: a) Creep
Explanation: Creep is the slow, time-dependent deformation of a material under constant stress or load, occurring at elevated temperatures.
8. What type of fatigue occurs due to repeated loading and unloading of a material?
a) Creep fatigue
b) Thermal fatigue
c) Mechanical fatigue
d) Fatigue failure
Answer: c) Mechanical fatigue
Explanation: Mechanical fatigue is the failure of a material due to repeated loading and unloading, leading to crack initiation and propagation.
9. Which term describes the ability of a material to resist indentation or scratching?
a) Strength
b) Hardness
c) Elasticity
d) Malleability
Answer: b) Hardness
Explanation: Hardness is the resistance of a material to indentation, scratching, or penetration.
10. What is the predominant element in industrial steel manufacturing?
a) Iron
b) Copper
c) Aluminum
d) Nickel
Answer: a) Iron
Explanation: Steel, an alloy primarily composed of iron and carbon, is a vital industrial material extensively used in various applications due to its strength and versatility.
11. Which prevailing manufacturing method involves shaping metal by pouring it into a mold and allowing it to cool and solidify?
a) Casting
b) Forging
c) Extrusion
d) Machining
Answer: a) Casting
Explanation: Casting is a manufacturing process wherein molten metal is poured into a mold cavity, allowed to solidify, and then removed to form the desired shape.
12. Which mechanical property refers to a material’s ability to resist external forces without breaking or deforming?
a) Strength
b) Hardness
c) Elasticity
d) Plasticity
Answer: a) Strength
Explanation: Strength is the mechanical property of a material that measures its ability to withstand applied forces without failure or deformation.
13. What type of bond is typically found in ceramic materials?
a) Ionic bond
b) Covalent bond
c) Metallic bond
d) Hydrogen bond
Answer: a) Ionic bond
Explanation: Ceramic materials often possess ionic bonding, where atoms transfer electrons to form positively and negatively charged ions, resulting in strong electrostatic attraction.
14. Which property refers to a material’s ability to be stretched or drawn into a wire?
a) Strength
b) Hardness
c) Malleability
d) Ductility
Answer: d) Ductility
Explanation: Ductility is the property of a material to deform plastically under tensile stress, allowing it to be stretched or drawn into a wire without fracturing.
15. What is the term for the state of a material when it exists in more than one crystal structure at the same time?
a) Polymorphism
b) Allotropy
c) Isomorphism
d) Eutectoid
Answer: b) Allotropy
Explanation: Allotropy is the phenomenon where a material exists in more than one crystal structure, typically occurring due to different arrangements of atoms or ions within the lattice.