General Science & Technology – Basics of Physics, Chemistry, and Biology
Assam Public Service Commission (APSC)
Combined Competitive Examination (CCE) – Preliminary Examination
General Studies Paper I (Objective, 200 Marks)
Topic: General Science & Technology
Sub-Topic: Basics of Physics, Chemistry, and Biology
Basics of Physics, Chemistry, and Biology – Multiple Choice Questions (MCQs) with Answers & Explanations
PHYSICS (Q1–Q10)
Q1. The SI unit of force is:
A. Joule
B. Newton
C. Watt
D. Pascal
Correct Answer: B
Explanation:
Force is measured in newtons (N), defined as the force required to accelerate a mass of 1 kg by 1 m/s².
Q2. Which law states that “for every action, there is an equal and opposite reaction”?
A. Newton’s First Law
B. Newton’s Second Law
C. Newton’s Third Law
D. Law of Gravitation
Correct Answer: C
Explanation:
Newton’s Third Law explains action–reaction pairs, fundamental to motion.
Q3. The speed of light in vacuum is approximately:
A. 3 × 10⁶ m/s
B. 3 × 10⁷ m/s
C. 3 × 10⁸ m/s
D. 3 × 10⁹ m/s
Correct Answer: C
Explanation:
Light travels at about 3 × 10⁸ m/s in vacuum.
Q4. Which form of energy is stored in a stretched rubber band?
A. Kinetic energy
B. Thermal energy
C. Chemical energy
D. Potential energy
Correct Answer: D
Explanation:
Energy stored due to position or shape change is potential energy.
Q5. The device used to measure electric current is:
A. Voltmeter
B. Ammeter
C. Galvanometer
D. Ohmmeter
Correct Answer: B
Explanation:
An ammeter measures electric current in amperes.
Q6. Which colour of light has the maximum wavelength?
A. Violet
B. Blue
C. Green
D. Red
Correct Answer: D
Explanation:
Red light has the longest wavelength in the visible spectrum.
Q7. Sound cannot travel through:
A. Air
B. Water
C. Steel
D. Vacuum
Correct Answer: D
Explanation:
Sound requires a material medium; it cannot propagate in vacuum.
Q8. Which phenomenon explains the bending of light around corners?
A. Reflection
B. Refraction
C. Diffraction
D. Dispersion
Correct Answer: C
Explanation:
Diffraction occurs when light bends around obstacles or apertures.
Q9. What is the unit of power?
A. Joule
B. Watt
C. Newton
D. Volt
Correct Answer: B
Explanation:
Power is the rate of doing work and is measured in watts (W).
Q10. The force that opposes motion between two surfaces in contact is:
A. Gravitational force
B. Magnetic force
C. Frictional force
D. Centrifugal force
Correct Answer: C
Explanation:
Friction resists relative motion between contacting surfaces.
CHEMISTRY (Q11–Q20)
Q11. The smallest unit of an element that retains its properties is:
A. Molecule
B. Atom
C. Ion
D. Compound
Correct Answer: B
Explanation:
An atom is the basic building block of matter.
Q12. Which gas is essential for combustion?
A. Nitrogen
B. Hydrogen
C. Oxygen
D. Carbon dioxide
Correct Answer: C
Explanation:
Oxygen supports combustion.
Q13. The pH value of a neutral solution is:
A. 0
B. 5
C. 7
D. 14
Correct Answer: C
Explanation:
Pure water has a neutral pH of 7.
Q14. Which substance is known as the universal solvent?
A. Alcohol
B. Ether
C. Water
D. Acetone
Correct Answer: C
Explanation:
Water dissolves many substances and is called the universal solvent.
Q15. Rusting of iron is an example of:
A. Physical change
B. Chemical change
C. Nuclear change
D. Reversible change
Correct Answer: B
Explanation:
Rusting forms a new substance (iron oxide), hence a chemical change.
Q16. Which gas is released during photosynthesis?
A. Carbon dioxide
B. Oxygen
C. Nitrogen
D. Hydrogen
Correct Answer: B
Explanation:
Plants release oxygen as a by-product of photosynthesis.
Q17. Which metal is liquid at room temperature?
A. Iron
B. Mercury
C. Sodium
D. Aluminium
Correct Answer: B
Explanation:
Mercury is the only metal liquid at room temperature.
Q18. The chemical formula of common salt is:
A. KCl
B. Na₂CO₃
C. NaCl
D. CaCl₂
Correct Answer: C
Explanation:
Common salt is sodium chloride (NaCl).
Q19. Which acid is present in lemon?
A. Acetic acid
B. Lactic acid
C. Citric acid
D. Oxalic acid
Correct Answer: C
Explanation:
Lemons contain citric acid, giving sour taste.
Q20. Which process is used to separate salt from seawater?
A. Filtration
B. Distillation
C. Evaporation
D. Sedimentation
Correct Answer: C
Explanation:
Salt is obtained by evaporation of seawater.
BIOLOGY (Q21–Q30)
Q21. The basic unit of life is:
A. Tissue
B. Organ
C. Cell
D. Organ system
Correct Answer: C
Explanation:
The cell is the structural and functional unit of life.
Q22. Which organ controls all activities of the human body?
A. Heart
B. Brain
C. Liver
D. Lungs
Correct Answer: B
Explanation:
The brain controls and coordinates body functions.
Q23. Photosynthesis takes place in which part of the plant cell?
A. Mitochondria
B. Nucleus
C. Chloroplast
D. Ribosome
Correct Answer: C
Explanation:
Chloroplasts contain chlorophyll for photosynthesis.
Q24. Which blood cells help in fighting infections?
A. Red blood cells
B. Platelets
C. White blood cells
D. Plasma
Correct Answer: C
Explanation:
White blood cells provide immunity.
Q25. The largest organ of the human body is:
A. Heart
B. Brain
C. Skin
D. Liver
Correct Answer: C
Explanation:
Skin is the largest organ by surface area.
Q26. Which vitamin is produced in the human body in sunlight?
A. Vitamin A
B. Vitamin B
C. Vitamin C
D. Vitamin D
Correct Answer: D
Explanation:
Sunlight helps synthesize Vitamin D in the skin.
Q27. Which organ is responsible for pumping blood?
A. Brain
B. Lungs
C. Heart
D. Kidney
Correct Answer: C
Explanation:
The heart pumps blood throughout the body.
Q28. Which gas is inhaled during respiration?
A. Carbon dioxide
B. Nitrogen
C. Oxygen
D. Hydrogen
Correct Answer: C
Explanation:
Humans inhale oxygen for cellular respiration.
Q29. The process by which plants lose water vapour is called:
A. Respiration
B. Transpiration
C. Photosynthesis
D. Germination
Correct Answer: B
Explanation:
Transpiration occurs mainly through leaf stomata.
Q30. Which microorganism is used in making curd?
A. Virus
B. Algae
C. Bacteria
D. Fungi
Correct Answer: C
Explanation:
Lactobacillus bacteria convert milk into curd.
✅ APSC Prelims Smart Tip
For General Science (Basics):
- Focus on definitions, units, and daily-life applications
- Revise basic laws, chemical properties, and biological processes
- Expect conceptual and application-based MCQs rather than numericals
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