CBSE Grade 12 Science (Physics, Chemistry, Biology) Exam Survival Guide

Window: Board Exam | Streams: Physics, Chemistry, Biology

Must-do topics

• Physics: Electrostatics (Coulomb, capacitors), Current electricity (Ohm’s, Kirchhoff’s), Magnetism, EMI & AC, Optics (ray/wave, devices), Dual nature, Atoms & nuclei, Semiconductor electronics
• Chemistry: Solid state, Solutions, Electrochemistry, Chemical kinetics, Surface chemistry, Coordination compounds, d/f-block elements, Haloalkanes/alcohols/phenols, Polymers, Biomolecules
• Biology: Reproduction (plants/animals), Genetics & Evolution (Mendel + molecular), Biology in human welfare (diseases, microbes, biotech), Biotechnology, Ecology, Environment

Top traps (avoid)

• Physics: sign convention errors, forgetting units in numericals
• Chem: missing balancing in redox; confusing rate order vs molecularity
• Bio: definitions without labeled diagrams; forgetting examples in biotech/ecology

Study split
Physics 35% | Chemistry 35% | Biology 30%

Last-48h checklist

• Physics: 20 numericals (electrostatics, optics, AC)
• Chemistry: 10 kinetics + 10 electrochem numericals; 10 organic conversions
• Biology: label 5 diagrams (meiosis, DNA structure, nephron, human heart, ecosystem cycles)

Quick facts/frames

• Physics: V=IRV=IRV=IR, Lens eqn 1/f=1/v−1/u1/f=1/v-1/u1/f=1/v−1/u, AC XL=ωL,XC=1/ωCX_L=ωL, X_C=1/ωCXL​=ωL,XC​=1/ωC
• Chem: Kc=[products]/[reactants]K_c=[products]/[reactants]Kc​=[products]/[reactants], ΔG=–nFE
• Bio: Central dogma DNA → RNA → Protein

Speed tactics

• Numericals: G–T–F–U (Given–To find–Formula–Unit)
• Chem: write reaction state symbols, box final conversion
• Bio: point-wise + diagram with labels

Exam-day mini-plan
Physics numericals early → Chem theory → Bio diagrams
Keep 15 min to recheck equations, labels, units