Free Chemical Process Principles MCQs with Answers

• A. Increases the strength
• B. Decreases the free carbon
• C. Softens it to facilitate machining
• D. None of these

Explanation: Annealing cast iron reduces hardness and relieves internal stresses, making the casting softer and easier to machine.

• A. 0.7-1.0
• B. 1.1-1.4
• C. 1.5 - 1.8
• D. 2.0 - 2.5

Explanation: Blast-furnace slag is commonly controlled with a basicity ratio near 1.1 to 1.4, based chiefly on the CaO-to-SiO2 relationship, with MgO…

• A. Creep
• B. Tension
• C. Compression
• D. Endurance

Explanation: Yield strength is obtained from a tensile test by identifying the stress at which permanent plastic deformation begins.

• A. Stainless steel tubes used in furnitures
• B. Aluminium curtain rods
• C. Cast iron pipe for domestic water supply
• D. Any of these

Explanation: Cast iron has poor ductility and is difficult to force through an extrusion die, so cast iron domestic water pipes are generally made by…

• A. Soluble in solid state
• B. Insoluble in liquid state
• C. Soluble in liquid state
• D. Insoluble in both solid & liquid state

Explanation: In a eutectic system, the components are completely soluble in the liquid phase and solidify at a specific eutectic composition and…

• A. Buffer
• B. Ideal
• C. Neutral
• D. Zero pH

Explanation: A buffer contains a weak acid and its conjugate base, or a weak base and its conjugate acid, which consume added H+ or OH− and resist pH…

• A. 3
• B. 7
• C. 11
• D. 15

Explanation: Escape velocity is given by √(2gR), so the body's mass cancels from the equation.

• A. Carbon dioxide
• B. Oxygen
• C. Carbon monoxide
• D. Air

Explanation: Carbon monoxide is the principal reducing gas in a blast furnace and removes oxygen from iron oxides to form iron.

• A. One
• B. None of these
• C. Three
• D. Two

Explanation: In closest packing, each atom is associated with one octahedral void and two tetrahedral voids.

• A. Magnesium
• B. Phosphorous
• C. Manganese
• D. Chromium

Explanation: Magnesium changes the graphite from flakes into rounded nodules, producing nodular or ductile cast iron.

• A. Spraying water
• B. Blanketting the area with nitrogen atmosphere
• C. Fire fighting foam
• D. None of these

Explanation: Nitrogen is inert and reduces the oxygen concentration around a fuel-gas fire, suppressing combustion without adding another combustible…

• A. Hard
• B. Elastic
• C. Ductile
• D. Brittle

Explanation: A fibrous fracture results from substantial plastic deformation before separation, which is characteristic of ductile materials.

• A. Ductile
• B. Tough
• C. Rigid
• D. Plastic

Explanation: Ductile materials undergo appreciable plastic deformation before fracture, whereas brittle materials fail at small strains.

• A. Equal
• B. More
• C. Less
• D. Double

Explanation: The elastic energy of an edge dislocation contains an additional factor of 1/(1−ν) compared with a screw dislocation.

• A. Promotes graphite module formation
• B. Improves its ductility
• C. Increases the fluidity of molten metal
• D. Does not promote graphite flakes formation

Explanation: Silicon is a graphitising element in cast iron and also improves the fluidity of the molten metal.

• A. Wrought iron
• B. Stainless steel
• C. Mild steel
• D. High speed steel

Explanation: High-speed steel retains hardness at the high temperatures produced during sawing, so it remains effective as a power-saw blade.

• A. Load to produce unit deflection
• B. Capacity to store energy
• C. Ratio of the wire & coil diameters
• D. Ability to absorb shock

Explanation: Spring stiffness is the force required to produce unit deflection, expressed as load divided by deflection.

• A. Grey cast iron
• B. Malleable iron
• C. Chilled cast iron
• D. White cast iron

Explanation: Malleable iron is comparatively ductile and tough, allowing it to absorb shock and vibration without cracking readily.

• A. Surface roughness
• B. Pores
• C. Spherical inclusion
• D. Crack

Explanation: A crack is the most dangerous manufacturing defect because its sharp tip produces a strong stress concentration and can initiate rapid…

• A. Tungsten
• B. Zirconium
• C. Molybdenum
• D. Tantalum

Explanation: Tungsten has the highest melting point among the listed metals, approximately 3422°C.