Multiple-Choice Questions (MCQs) (Curiosity–Science Class 8):

🧠 MCQs from Chapter 1 – Exploring the Investigative World of Science

1. What does scientific investigation primarily begin with?
   a) Memorizing facts
   b) Asking questions
   c) Performing experiments only
   d) Reading textbooks
   Answer: b) Asking questions​
2. What is the main focus of Grade 8 science as described in the book?
   a) Collecting data from others
   b) Learning how to find new facts through investigation
   c) Memorizing definitions
   d) Performing complex mathematical calculations
   Answer: b) Learning how to find new facts through investigation​
3. What do the symbols ‘root’ and ‘kite’ in the textbook represent?
   a) Food and flight
   b) Knowledge and curiosity
   c) Stability and exploration
   d) Water and air
   Answer: c) Stability and exploration​
4. Which of the following helps us to stay healthy according to the chapter?
   a) Junk food and rest
   b) Nutritious food, exercise, medicines, and vaccines
   c) Pollution and chemicals
   d) Avoiding physical activity
   Answer: b) Nutritious food, exercise, medicines, and vaccines​
5. ★The heating and magnetic effects mentioned in the chapter are produced by:
   a) Kinetic energy
   b) Electric current
   c) Chemical reactions
   d) Light energy
   Answer: b) Electric current​
6. ★What physical quantity explains why a car stops when brakes are applied?
   a) Energy
   b) Pressure
   c) Force
   d) Momentum
   Answer: c) Force​
7. ★A small difference in air pressure can cause:
   a) Thunderstorms only
   b) Earthquakes
   c) Gentle breezes or strong winds
   d) No effect at all
   Answer: c) Gentle breezes or strong winds​
8. ★ What determines whether materials are solids, liquids, or gases?
   a) The color of the material
   b) The type of bonding only
   c) The movement of particles
   d) Their weight
   Answer: c) The movement of particles​
9. A mixture can be separated using:
   a) Physical methods
   b) Chemical bonding
   c) Magnetic forces only
   d) Electrical charge
   Answer: a) Physical methods​
10. ★When sugar dissolves in tea, what kind of mixture is formed?
    a) Suspension
    b) Compound
    c) Solution
    d) Colloid
    Answer: c) Solution​
11. ★Which phenomenon explains why corrective glasses help us see clearly?
    a) Reflection of light
    b) Bending (refraction) of light through lenses
    c) Absorption of light
    d) Diffraction of light
    Answer: b) Bending (refraction) of light through lenses​
12. Why does the Moon appear differently each night?
    a) It changes shape
    b) Different parts of it are illuminated by the Sun
    c) The Earth moves closer to the Moon
    d) Clouds cover part of it
    Answer: b) Different parts of it are illuminated by the Sun​
13. ★The first human calendars were based on:
    a) Solar and lunar cycles
    b) Random counting
    c) Movements of Jupiter
    d) Ocean tides
    Answer: a) Solar and lunar cycles​
14. ★The relationships among organisms and their environments form:
    a) Ecosystems
    b) Atmosphere
    c) Biosphere only
    d) Hydrosphere
    Answer: a) Ecosystems​
15. ★Earth is suitable for life mainly because:
    a) It is made entirely of rock
    b) It has liquid water and a protective atmosphere
    c) It has more sunlight
    d) It has a thick layer of carbon dioxide
    Answer: b) It has liquid water and a protective atmosphere​
16. ★Changes in Earth’s temperature due to human activities mainly affect:
    a) Tides
    b) Climate patterns
    c) Moon’s orbit
    d) Seasons only
    Answer: b) Climate patterns​
17. The most important tool of science for solving global problems is:
    a) Curiosity and observation
    b) Guesswork
    c) Superstition
    d) Political debate
    Answer: a) Curiosity and observation​
18. Why does a puri puff up when fried?
    a) Due to water vapor forming inside the dough when heated
    b) Because of air pressure from outside
    c) Because it has holes
    d) Because it burns
    Answer: a) Due to water vapor forming inside the dough when heated​
19. What principle does the puri experiment demonstrate?
    a) Systematic investigation
    b) Trial without recording
    c) Random mixing
    d) Blind testing
    Answer: a) Systematic investigation​
20. What key attitude does the textbook encourage in young scientists?
    a) Memorization of facts
    b) Curiosity and careful observation
    c) Avoiding mistakes
    d) Copying old experiments
    Answer: b) Curiosity and careful observation​

🧠 MCQs from Chapter 2: The Invisible Living World Beyond Our Naked Eye

1. Which instrument allows us to see microorganisms clearly?
   a) Telescope
   b) Magnifying glass
   c) Microscope
   d) Prism
   Answer: c) Microscope​
2. ★ Who first used the term “cell” while observing cork under a microscope?
   a) Antonie van Leeuwenhoek
   b) Robert Hooke
   c) Galileo Galilei
   d) Louis Pasteur
   Answer: b) Robert Hooke​
3. ★ Antonie van Leeuwenhoek is known as the:
   a) Father of Chemistry
   b) Father of Microbiology
   c) Father of Botany
   d) Father of Medicine
   Answer: b) Father of Microbiology​
4. ★ The basic unit of life is the:
   a) Tissue
   b) Organ
   c) Cell
   d) Atom
   Answer: c) Cell​
5. What does the cell membrane primarily do?
   a) Provides rigidity
   b) Allows the exchange of substances
   c) Stores food
   d) Produces energy
   Answer: b) Allows the exchange of substances​
6. Which part of the cell regulates all activities of the cell?
   a) Cytoplasm
   b) Nucleus
   c) Cell wall
   d) Vacuole
   Answer: b) Nucleus​
7. ★Which additional layer do plant cells have that animal cells lack?
   a) Cytoplasm
   b) Mitochondria
   c) Cell wall
   d) Nucleus
   Answer: c) Cell wall​
8. The green pigment chlorophyll is found in which cell structure?
   a) Chloroplast
   b) Cytoplasm
   c) Nucleus
   d) Mitochondria
   Answer: a) Chloroplast​
9. Vacuoles in plant cells help in:
   a) Producing chlorophyll
   b) Maintaining shape and storing substances
   c) Conducting impulses
   d) Energy production
   Answer: b) Maintaining shape and storing substances​
10. A group of similar cells that perform a specific function form a:
    a) Tissue
    b) Organ
    c) Organ system
    d) Organism
    Answer: a) Tissue​
11. ★Which of the following is the correct order of biological organization?
    a) Cell → Organ → Tissue → Organism
    b) Cell → Tissue → Organ → Organ system → Organism
    c) Organ → Tissue → Cell → Organ system
    d) Tissue → Cell → Organ system → Organism
    Answer: b) Cell → Tissue → Organ → Organ system → Organism​
12. Single-celled organisms are called:
    a) Multicellular
    b) Unicellular
    c) Acellular
    d) Eukaryotic
    Answer: b) Unicellular​
13. Which scientist developed a bacterium that can break down oil spills?
    a) Robert Hooke
    b) Dr. A. M. Chakrabarty
    c) Isaac Newton
    d) Gregor Mendel
    Answer: b) Dr. A. M. Chakrabarty​
14. Yeast belongs to which group of microorganisms?
    a) Bacteria
    b) Fungi
    c) Protozoa
    d) Algae
    Answer: b) Fungi​
15. ★During fermentation by yeast, which gas is released to make dough fluffy?
    a) Oxygen
    b) Nitrogen
    c) Carbon dioxide
    d) Hydrogen
    Answer: c) Carbon dioxide​
16. Which bacterium helps in the formation of curd?
    a) E. coli
    b) Rhizobium
    c) Lactobacillus
    d) Salmonella
    Answer: c) Lactobacillus​
17. ★The bacterium Rhizobium is beneficial because it:
    a) Causes diseases in humans
    b) Traps nitrogen for leguminous plants
    c) Produces curd
    d) Makes bread soft
    Answer: b) Traps nitrogen for leguminous plants​
18. ★Microalgae like Spirulina are important because they:
    a) Produce oxygen and are rich in nutrients
    b) Absorb all the water in ponds
    c) Cause pollution
    d) Are harmful to aquatic life
    Answer: a) Produce oxygen and are rich in nutrients​
19. ★Viruses differ from other microorganisms because they:
    a) Are visible to the naked eye
    b) Can reproduce without a host
    c) Reproduce only inside a living cell
    d) Are multicellular
    Answer: c) Reproduce only inside a living cell​
20. ★Which of the following cells does not have a well-defined nucleus?
    a) Algae
    b) Fungi
    c) Bacteria
    d) Yeast
    Answer: c) Bacteria​

🧠 MCQs from Chapter 3: Health – The Ultimate Treasure

1. According to the World Health Organization (WHO), health means:
   a) Absence of disease
   b) Complete physical, mental, and social well-being
   c) Being free from infections only
   d) Having good physical strength
   Answer: b) Complete physical, mental, and social well-being​
2. ★Which ancient Indian system emphasizes balance between body, mind, and surroundings?
   a) Yoga Sutra
   b) Ayurveda
   c) Siddha
   d) Unani
   Answer: b) Ayurveda​
3. Which of the following is NOT a good health habit?
   a) Eating balanced food
   b) Maintaining personal hygiene
   c) Sleeping late and skipping meals
   d) Regular exercise
   Answer: c) Sleeping late and skipping meals​
4. ★The natural system of the body that fights against diseases is called:
   a) Circulatory system
   b) Digestive system
   c) Immune system
   d) Nervous system
   Answer: c) Immune system​
5. Which of the following is a communicable disease?
   a) Cancer
   b) Diabetes
   c) Typhoid
   d) Asthma
   Answer: c) Typhoid​
6. ★Non-communicable diseases are mostly caused by:
   a) Germs
   b) Pathogens
   c) Lifestyle and environment
   d) Contaminated food
   Answer: c) Lifestyle and environment​
7. ★Which disease is transmitted through mosquito bites?
   a) Cholera
   b) Dengue
   c) Typhoid
   d) Tuberculosis
   Answer: b) Dengue​
8. Cholera spreads mainly through:
   a) Mosquito bites
   b) Contaminated food and water
   c) Airborne droplets
   d) Animal bites
   Answer: b) Contaminated food and water​
9. ★The causal agent for malaria is:
   a) Bacterium
   b) Protozoa
   c) Worm
   d) Virus
   Answer: b) Protozoa​
10. Which of the following is a symptom, not a sign?
    a) Fever
    b) Rash
    c) Pain
    d) Swelling
    Answer: c) Pain​
11. ★The first vaccine in history was developed by:
    a) Louis Pasteur
    b) Edward Jenner
    c) Alexander Fleming
    d) Robert Koch
    Answer: b) Edward Jenner​
12. ★Vaccines provide protection by developing:
    a) Antibodies
    b) Hormones
    c) Blood cells
    d) Enzymes
    Answer: a) Antibodies​
13. The first antibiotic discovered was:
    a) Tetracycline
    b) Penicillin
    c) Ampicillin
    d) Streptomycin
    Answer: b) Penicillin​
14. Who discovered penicillin?
    a) Robert Hooke
    b) Alexander Fleming
    c) Edward Jenner
    d) Louis Pasteur
    Answer: b) Alexander Fleming​
15. ★Antibiotics are used to treat diseases caused by:
    a) Bacteria
    b) Viruses
    c) Worms
    d) Protozoa
    Answer: a) Bacteria​
16. ★Excessive use of antibiotics can lead to:
    a) Faster recovery
    b) Antibiotic resistance
    c) Reduced fever
    d) Stronger immunity
    Answer: b) Antibiotic resistance​
17. Which of the following diseases is non-communicable?
    a) Measles
    b) Common cold
    c) Asthma
    d) Chickenpox
    Answer: c) Asthma​
18. Dr. Kamal Ranadive is known for her research in:
    a) Diabetes
    b) Immunology
    c) Cancer
    d) Viral infections
    Answer: c) Cancer​
19. India eradicated smallpox through:
    a) Sanitation campaigns
    b) Mass vaccination programs
    c) Antibiotic use
    d) Quarantine laws
    Answer: b) Mass vaccination programs​
20. ★The harmful effect of taking antibiotics unnecessarily is:
    a) Improved digestion
    b) Killing useful bacteria in the body
    c) Increased appetite
    d) Enhanced immunity
    Answer: b) Killing useful bacteria in the body​

🧠 MCQs from Chapter 4: Electricity – Magnetic and Heating Effects

1. ★When an electric current flows through a conductor, it produces:
   a) Heat only
   b) Light only
   c) A magnetic field
   d) A chemical reaction
   Answer: c) A magnetic field​
2. ★The scientist who discovered that electric current produces a magnetic field was:
   a) Newton
   b) Faraday
   c) Hans Christian Ørsted
   d) Volta
   Answer: c) Hans Christian Ørsted​
3. A coil of wire carrying current behaves like:
   a) An insulator
   b) A magnet
   c) A conductor without effect
   d) A resistor
   Answer: b) A magnet​
4. ★The region around a magnet where its effect can be felt is called:
   a) Magnetic charge
   b) Magnetic effect
   c) Magnetic field
   d) Magnetic pole
   Answer: c) Magnetic field​
5. When the current in a circuit stops, the magnetic effect:
   a) Becomes stronger
   b) Remains the same
   c) Disappears
   d) Doubles
   Answer: c) Disappears​
6. An electromagnet is made using:
   a) A non-metal wire and magnet
   b) A coil of current-carrying wire, often with an iron core
   c) A permanent magnet with copper wire
   d) A static electric charge
   Answer: b) A coil of current-carrying wire, often with an iron core​
7. ★Which material is most commonly used as the core of electromagnets?
   a) Aluminum
   b) Iron
   c) Copper
   d) Carbon
   Answer: b) Iron​
8. The polarity of an electromagnet can be reversed by:
   a) Increasing number of turns in the coil
   b) Using a longer wire
   c) Changing direction of current
   d) Replacing the core
   Answer: c) Changing direction of current​
9. The strength of an electromagnet increases when:
   a) Current is reduced
   b) Number of turns in coil is increased
   c) Core is removed
   d) Magnet poles are reversed
   Answer: b) Number of turns in coil is increased​
10. ★The Earth behaves like:
    a) An insulator
    b) A large magnet
    c) A static conductor
    d) A dense core of copper
    Answer: b) A large magnet​
11. ★Lifting electromagnets are used in:
    a) Hospitals
    b) Scrap yards and factories
    c) Classrooms
    d) Optical labs
    Answer: b) Scrap yards and factories​
12. The heating effect of electric current is caused by:
    a) Magnetic resistance
    b) Frictional loss in wire
    c) Resistance to current flow in the conductor
    d) Vibration of atoms only
    Answer: c) Resistance to current flow in the conductor​
13. Wire that is commonly used in heaters and toasters:
    a) Copper
    b) Nichrome
    c) Iron
    d) Zinc
    Answer: b) Nichrome​
14. ★When the thickness of a wire increases, the resistance:
    a) Increases
    b) Decreases
    c) Remains same
    d) Becomes infinite
    Answer: b) Decreases​
15. Which device works on the heating effect of electric current?
    a) Electric fan
    b) Loudspeaker
    c) Electric iron
    d) Computer
    Answer: c) Electric iron​
16. ★In which household appliance can the heating element be seen glowing red hot?
    a) Water heater
    b) Electric stove
    c) Ceiling fan
    d) Television
    Answer: b) Electric stove​
17. The device that generates electricity using chemical reactions is called:
    a) Electromagnet
    b) Electric cell
    c) Heating coil
    d) Generator
    Answer: b) Electric cell​
18. ★The scientist who invented the first battery was:
    a) Volta
    b) Edison
    c) Tesla
    d) Coulomb
    Answer: a) Volta​
19. ★The electrolyte used in Voltaic cells is typically:
    a) Pure water
    b) Acid or salt solution
    c) Alcohol
    d) Sand-water mixture
    Answer: b) Acid or salt solution​
20. Rechargeable batteries are eco-friendly because:
    a) They can be reused many times
    b) They are made of plastic
    c) They discharge automatically
    d) They generate magnetic fields
    Answer: a) They can be reused many times​

🧠 MCQs from Chapter 5: Exploring Forces

1. What is a force in science?
   a) A type of energy
   b) Push or pull on an object
   c) Change in temperature
   d) A type of motion
   Answer: b) Push or pull on an object
2. Which of the following is an example of muscular force?
   a) Magnetic force
   b) Force when pushing a box
   c) Gravitational force
   d) Electrostatic force
   Answer: b) Force when pushing a box
3. ★Frictional force always acts:
   a) In the direction of motion
   b) Opposite to the direction of motion
   c) At right angles to motion
   d) Randomly
   Answer: b) Opposite to the direction of motion
4. Friction is usually greater on:
   a) Smooth surfaces
   b) Rough surfaces
   c) Wet surfaces
   d) Polished surfaces
   Answer: b) Rough surfaces
5. ★Which force can act without physical contact?
   a) Muscular force
   b) Frictional force
   c) Magnetic force
   d) Applied force
   Answer: c) Magnetic force
6. Magnetic poles with the same polarity:
   a) Attract each other
   b) Repel each other
   c) Have no effect on each other
   d) Always remain neutral
   Answer: b) Repel each other
7. ★When two balloons rubbed with wool move away from each other, it shows that:
   a) They are uncharged
   b) They have similar charges
   c) They have opposite charges
   d) They are magnets
   Answer: b) They have similar charges
8. ★The force exerted by a charged object on another object without contact is called:
   a) Magnetic force
   b) Gravitational force
   c) Electrostatic force
   d) Applied force
   Answer: c) Electrostatic force
9. Gravitational force is:
   a) Repulsive force
   b) Attractive force
   c) Both attractive and repulsive
   d) None of these
   Answer: b) Attractive force
10. ★Weight of an object is the force due to:
    a) Magnetic field
    b) Electrostatic charges
    c) Gravitational pull of Earth
    d) Push by air
    Answer: c) Gravitational pull of Earth
11. SI unit of force is:
    a) Joule
    b) Newton
    c) Pascal
    d) Watt
    Answer: b) Newton
12. Which of the following is used to measure weight?
    a) Thermometer
    b) Spring balance
    c) Stopwatch
    d) Ruler
    Answer: b) Spring balance
13. ★If an object is floating in water, the upward force is called:
    a) Gravity
    b) Buoyant force
    c) Magnetic force
    d) Friction
    Answer: b) Buoyant force
14. ★Archimedes’ principle states that:
    a) Upthrust on an object is equal to the weight of the object
    b) Upthrust on an object is equal to the weight of liquid displaced
    c) Weight in water is always more than weight in air
    d) Buoyant force is always zero
    Answer: b) Upthrust on an object is equal to the weight of liquid displaced
15. ★Pumice floats on water because:
    a) It has air pockets
    b) It is heavy
    c) It is magnetic
    d) It is dense
    Answer: a) It has air pockets
16. Friction is helpful when:
    a) We want to walk
    b) We want to slide easily
    c) We want objects to move without resistance
    d) A ball rolls on a smooth surface
    Answer: a) We want to walk
17. Friction creates:
    a) Heat
    b) Cooling
    c) Light
    d) Sound only
    Answer: a) Heat
18. ★Force can change:
    a) Speed of an object
    b) Direction of an object
    c) Shape of an object
    d) All of the above
    Answer: d) All of the above
19. ★When a ball is thrown upwards, the force acting on it is:
    a) Only upward force
    b) Only gravitational force downward
    c) No force
    d) Electrostatic force
    Answer: b) Only gravitational force downward
20. The force that opposes motion of sliding objects is called:
    a) Magnetic force
    b) Electrostatic force
    c) Frictional force
    d) Gravitational force
    Answer: c) Frictional force