General Science Physics Chemistry Biology Class 10 Questions for BIHAR POLICE CONSTABLE

Physics: Motion, Force, and Energy

Physics questions in Bihar Police exams test practical understanding of how things move and interact. You need to know Newton's three laws of motion, the difference between speed and velocity, and basic energy concepts. These are not calculation-heavy; they test conceptual clarity. For example, why a seatbelt saves you in a car crash (inertia), or why a heavier object needs more force to move (F=ma). The exam also covers simple machines like pulleys and levers, which appear in daily life.

• Newton's First Law: Object at rest stays at rest unless external force acts (inertia)
• Newton's Second Law: Force = Mass × Acceleration (F=ma); more mass or acceleration = more force needed
• Newton's Third Law: Every action has equal and opposite reaction
• Speed is distance/time; Velocity is displacement/time with direction
• Energy cannot be created or destroyed, only converted (law of conservation)
• Work = Force × Distance; Power = Work/Time

Chemistry: Atoms, Reactions, and Acids-Bases

Chemistry in Bihar Police GK focuses on what atoms are, how they bond, and how substances react. You should understand the periodic table basics (hydrogen, oxygen, carbon, nitrogen), what acids and bases do, and common chemical reactions in daily life. Rusting of iron, burning of fuel, digestion in stomach (acid), and cleaning with soap (base) are exam favorites. Know the difference between physical and chemical changes: physical change is reversible (melting ice), chemical change is not (burning paper).

• Atom = smallest unit of element; Molecule = two or more atoms bonded
• Acids taste sour, turn blue litmus red, pH < 7 (e.g., lemon juice, vinegar)
• Bases taste bitter, turn red litmus blue, pH > 7 (e.g., soap, baking soda)
• Neutral substance has pH = 7 (pure water)
• Chemical reaction: reactants → products; cannot be easily reversed
• Oxidation = loss of electrons or gain of oxygen; Rusting is oxidation

Biology: Cells, Life Processes, and Ecosystems

Biology questions test knowledge of living organisms, how they function, and how they interact. Cell structure (nucleus, mitochondria, chloroplast) is common. You need to know photosynthesis (plants make food using sunlight), respiration (all organisms break down food for energy), and reproduction (sexual vs asexual). Human body systems—digestive, circulatory, respiratory, nervous—appear frequently. Ecosystems and food chains also show up: producers (plants) → consumers (animals) → decomposers (bacteria).

• Cell = basic unit of life; Nucleus controls cell activities
• Mitochondria = powerhouse of cell; produces energy (ATP)
• Chloroplast = found in plants; site of photosynthesis
• Photosynthesis: Plants use sunlight, water, CO2 to make glucose and oxygen
• Respiration: All organisms break down glucose to release energy
• Reproduction: Sexual (two parents, genetic variation) vs Asexual (one parent, identical)

Human Body Systems

Bihar Police exams frequently ask about how the human body works. Focus on the major systems: digestive (mouth → stomach → intestines), circulatory (heart pumps blood), respiratory (lungs exchange O2 and CO2), and nervous (brain controls everything). Know key organs: heart (pumps blood), lungs (gas exchange), brain (control center), liver (filters blood), kidneys (filter waste). These appear as definition questions or 'which organ does this' questions.

• Digestive system: Breaks down food into nutrients; starts in mouth, ends in small intestine
• Circulatory system: Heart pumps blood through arteries and veins to all cells
• Respiratory system: Lungs absorb oxygen, release carbon dioxide
• Nervous system: Brain and spinal cord control all body functions
• Excretory system: Kidneys filter waste, produce urine
• Endocrine system: Glands produce hormones (e.g., insulin controls blood sugar)

Ecology and Food Chains

Ecology questions ask how organisms live together and depend on each other. A food chain shows energy flow: grass (producer) → rabbit (primary consumer) → fox (secondary consumer). Decomposers (bacteria, fungi) break down dead matter and return nutrients to soil. Biodiversity means variety of species; more biodiversity = healthier ecosystem. Pollution and deforestation harm ecosystems. These are straightforward conceptual questions.

• Producer = makes own food (plants via photosynthesis)
• Consumer = eats other organisms (herbivore, carnivore, omnivore)
• Decomposer = breaks down dead matter (bacteria, fungi)
• Food chain = linear path of energy; Food web = multiple interconnected chains
• Ecosystem = all organisms + environment in an area
• Biodiversity = variety of species; supports ecosystem stability

• Confusing Speed and Velocity: Speed is just how fast (50 km/h); Velocity includes direction (50 km/h north). Exam asks 'which is a vector' — velocity is the answer.
• Mixing up Acids and Bases: Remember — Acids are sour (lemon), Bases are bitter (soap). pH < 7 is acid, pH > 7 is base. Don't reverse it.
• Thinking Photosynthesis and Respiration are Opposites: They're not exact opposites. Photosynthesis stores energy; respiration releases it. Both happen in plants, but photosynthesis only in light.
• Forgetting Mitochondria in Plant Cells: Students think mitochondria are only in animal cells. Wrong — plants have both mitochondria (for respiration) AND chloroplasts (for photosynthesis).
• Confusing Physical and Chemical Changes: Melting ice is physical (reversible); burning paper is chemical (irreversible). Exam often asks 'which is reversible' — choose the physical one.

• Newton's Laws = INR: Inertia (1st), Net force = ma (2nd), Reaction (3rd)
• Acid-Base = pH: Below 7 = Acid, Above 7 = Base, 7 = Neutral (BAB mnemonic: Below Acid, Above Base)
• Cell Organelles = MNRC: Mitochondria (energy), Nucleus (control), Ribosome (protein), Chloroplast (food-making)
• Food Chain = PCD: Producer (plant) → Consumer (animal) → Decomposer (bacteria)
• Body Systems = DCRNE: Digestive, Circulatory, Respiratory, Nervous, Excretory

• Bihar Police GK science section rarely has calculations — focus on definitions and 'which organ/process does this' questions. Practice with previous year papers to see the pattern.
• Practical applications are heavily tested: Why does ice float? (density), Why do we need oxygen? (respiration), Why is photosynthesis important? (food + oxygen). Think real-world.
• Multiple-choice format means one option is obviously wrong. Eliminate it first. For example, if asked 'which is an acid', options like 'soap' or 'baking soda' are instant eliminations.
• Time pressure is real — aim to spend max 1 minute per question. If unsure, use logic: 'What makes sense in daily life?' Photosynthesis = plants making food in sunlight is common sense.
• Recent Bihar Police papers show increased focus on human body systems and ecology. Spend extra time on digestive, circulatory, and food chain concepts.