Material Around Us Part 4: MCQs (Q76–Q100)
Part 4 — Questions 76–100 (Environment, health & safety, materials selection, revision & mixed practice)
76. Which of the following best describes non-biodegradable material?
A. Decomposes rapidly into soil nutrients
B. Does not break down easily; remains in environment for long time ← Correct answer: B
C. Always edible by microbes quickly
D. Grows naturally in soil
Explanations:
A/C/D) Opposite of non-biodegradable.
B) Correct — plastics and polythene often persist in nature for centuries.
77. For food storage to avoid chemical reactions with food, which container is best?
A. Lead container
B. Copper uncoated container for acidic foods
C. Food-grade stainless steel or glass ← Correct answer: C
D. Bare iron container for long term storage of acidic items
Explanations:
A/B/D) Metals like lead or uncoated copper can contaminate or react with food.
C) Correct — stainless steel and glass are non-reactive and safe for food storage.
78. Which of the following is true about plastics?
A. All plastics are biodegradable and safe for environment
B. Some plastics are recyclable; others persist as waste ← Correct answer: B
C. Plastics are metals in disguise
D. Plastics always conduct electricity well
Explanations:
A/C/D) False statements.
B) Correct — recycling depends on plastic type; many are persistent pollutants.
79. Which material is best for making thermal insulation in houses (to reduce heat flow)?
A. Metal sheets
B. Foam, fiberglass, or wood (insulators) ← Correct answer: B
C. Copper plates
D. Wet cloths
Explanations:
A/C) Metals conduct heat, poor insulators.
B) Correct — foam/fiberglass/wood are insulating materials slowing heat transfer.
D) Wet cloth transfers heat via water and is not suitable.
80. Which property is most important for selecting material for making a flexible water pipe?
A. High brittleness
B. Flexibility and water resistance ← Correct answer: B
C. High electrical conductivity
D. High transparency only
Explanations:
A/C/D) Unsuitable properties.
B) Correct — water pipes need to bend without cracking and resist water.
81. Which material should NOT be used to store acidic pickles for long?
A. Glass jar
B. Aluminium uncoated ← Correct answer: B
C. Food-grade plastic (appropriate)
D. Ceramic glazed jar
Explanations:
A/C/D) Safe choices.
B) Correct — aluminium can react with acids and contaminate food.
82. Which of the following materials is best for making long-lasting outdoor benches?
A. Untreated wood only
B. Teak or treated hardwood/metal with protective coating ← Correct answer: B
C. Paper pulp
D. Sponge
Explanations:
A/C/D) Unsuitable for long outdoor use without treatment.
B) Correct — teak and treated materials resist weathering.
83. Which method helps reduce plastic pollution?
A. Burning plastics openly (releases toxic fumes)
B. Reduce, reuse and recycle plastics; use alternatives ← Correct answer: B
C. Dumping plastics in rivers
D. Making smaller plastic packets but same usage frequency
Explanations:
A/C/D) Harmful or ineffective.
B) Correct — waste hierarchy and alternatives reduce pollution.
84. Which material is habitually used in electrical plugs and sockets as an insulator?
A. Metal body without covering
B. Bakelite or molded plastic ← Correct answer: B
C. Bare copper
D. Glass (fragile)
Explanations:
A/C) Metals conduct electricity and unsafe.
B) Correct — Bakelite/plastic insulates and withstands heat.
D) Fragility and installation issues make glass unsuitable.
85. A material with low density and good cushioning is ideal for packaging fragile items. Which is commonly used?
A. Lead sheets
B. Polystyrene foam or bubble wrap ← Correct answer: B
C. Glass plates
D. Metal bolts
Explanations:
A/C/D) Not cushioning or too heavy.
B) Correct — lightweight foams and bubble wraps cushion and protect fragile goods.
86. Which of the following demonstrates that copper is ductile?
A. It can be hammered into thin sheets only (malleable)
B. It can be drawn into thin wires ← Correct answer: B
C. It dissolves in water easily
D. It shatters on impact
Explanations:
A) Hammering into sheets is malleability (copper is both ductile and malleable).
B) Correct — ductility refers to drawing into wires.
C/D) Incorrect.
87. Which material would you choose for a baby’s feeding spoon to avoid chemical leaching and heat conduction?
A. Bare aluminium (untreated)
B. Food-grade plastic (BPA-free) or stainless steel with insulated handle ← Correct answer: B
C. Lead spoon
D. Painted iron with peeling paint
Explanations:
A/C/D) Risky due to reactivity/toxicity or paint contamination.
B) Correct — safe, non-reactive materials are best for baby feeding.
88. Which is the best reason to recycle aluminum cans?
A. Aluminum cannot be melted and reused
B. Recycling saves energy and raw materials compared to extracting new aluminum ← Correct answer: B
C. Recycling makes cans heavier always
D. Recycling turns aluminum into wood
Explanations:
A/C/D) False.
B) Correct — recycling aluminum is energy efficient and reduces mining.
89. Which material property is most important for safety glass in vehicles?
A. High transparency only
B. Shatter-resistance or laminated/tempered behavior (breaks into small blunt pieces) ← Correct answer: B
C. High magnetism
D. High magnetic permeability
Explanations:
A) Transparency important but safety requires shatter resistance.
B) Correct — tempered/laminated glass breaks safely to reduce injuries.
C/D) Irrelevant.
90. Which of the following materials is suitable for making a kite because it is light and somewhat tear resistant?
A. Heavy metal sheet
B. Light plastic film or strong paper ← Correct answer: B
C. Brick slab
D. Thick glass plate
Explanations:
A/C/D) Too heavy/unsafe.
B) Correct — light materials allow flight and resist tearing to some extent.
91. Which of the following is NOT a standard safety practice when handling materials in a lab?
A. Wearing gloves and goggles where needed
B. Tasting unknown chemicals to identify them ← Correct answer: B
C. Reading labels and instructions before use
D. Using proper storage and disposal methods
Explanations:
A/C/D) Correct safety practices.
B) Incorrect and dangerous — never taste chemicals.
92. Which material is used to make footprints/sole of industrial heavy-duty boots for grip?
A. Smooth glass
B. Hard wearing rubber with tread patterns ← Correct answer: B
C. Polished marble
D. Ice
Explanations:
A/C/D) Slippery or unsafe surfaces.
B) Correct — rubber soles with treads provide grip and durability.
93. Which property is desirable for materials used in greenhouse covering to allow light but trap heat?
A. Opaque and reflective only
B. Transparent to visible light but with heat-retaining properties (greenhouse effect) ← Correct answer: B
C. Highly magnetic
D. Heavy and unbendable
Explanations:
A/C/D) Unsuitable.
B) Correct — greenhouse coverings transmit light and trap infrared to warm interior.
94. Which of the following plastics is commonly recycled and used to make bottles?
A. PVC only (rarely recycled in some streams)
B. PET (polyethylene terephthalate) ← Correct answer: B
C. Polyurethane foam (difficult to recycle widely)
D. Asbestos sheets
Explanations:
A/C/D) Some are hard to recycle or hazardous.
B) Correct — PET is widely recycled and used for beverage bottles.
95. In choosing material for making a pencil lead, which property is important?
A. High electrical conductivity
B. Ability to leave a visible mark on paper and be break-resistant enough ← Correct answer: B
C. High solubility in water
D. High transparency
Explanations:
A/C/D) Irrelevant to pencil marking.
B) Correct — pencil leads (graphite-clay) must mark paper and resist easy breakage.
96. Which of the following is a health risk from asbestos (historical building material)?
A. Improved breathing quality always
B. Respiratory diseases including asbestosis and cancer when fibres inhaled ← Correct answer: B
C. Makes water potable always
D. Enhances sunlight transmission only
Explanations:
A/C/D) False.
B) Correct — asbestos fibres are hazardous if inhaled, causing lung disease.
97. Which of these materials is used where high temperature resistance is required (e.g., furnace lining)?
A. Regular wood panels
B. Fire-brick or refractory ceramics ← Correct answer: B
C. Thin plastic sheets
D. Cotton cloth
Explanations:
A/C/D) Flammable or melt at high heat.
B) Correct — refractory bricks resist very high temperatures.
98. Which of the following is an eco-friendly alternative to single-use plastic bags?
A. More polythene bags
B. Cloth bags or reusable jute bags ← Correct answer: B
C. Burning plastic bags locally
D. Dumping plastic in fields
Explanations:
A/C/D) Continue pollution or create hazards.
B) Correct — reusable cloth/jute reduce plastic waste.
99. Which material is best for making a microscope lens (optical quality)?
A. Ordinary window glass with impurities
B. Optical-grade glass or clear acrylic with controlled refractive index ← Correct answer: B
C. Rusty metal plate
D. Sand
Explanations:
A/C/D) Impure or inappropriate materials.
B) Correct — optical glass/acrylic is manufactured for lens clarity and refractive accuracy.
100. Final quick revision — which is a correct concise summary about materials?
A. All materials are identical and have same properties
B. Materials are chosen for applications based on properties (strength, conductivity, solubility, elasticity, biodegradability) ← Correct answer: B
C. Materials never change with environment
D. Only metals are useful materials
Explanations:
A/C/D) Incorrect generalizations.
B) Correct — selecting materials depends on matching properties to required use and environmental considerations.