General Science — SSC GD Study Notes

Overview

General Science forms a critical pillar of the GK section in SSC GD, typically contributing 15–20 questions from Physics, Chemistry and Biology combined. This topic tests fundamental concepts at the matriculation level — the kind of science you encounter in daily life and read about in newspapers. Success here doesn't require deep theoretical knowledge but demands clarity on basic principles, definitions and real-world applications.

Questions are direct and factual: "Which vitamin deficiency causes scurvy?", "What is the SI unit of force?", or "Which gas is released during photosynthesis?" The exam rarely asks derivations or calculations but frequently tests your ability to connect concepts to everyday phenomena — why iron rusts, how vaccines work, or what causes tides. Students who revise NCERT Class 6–10 science textbooks thoroughly and stay updated on science-related current affairs (ISRO missions, Nobel prizes in science, new discoveries) score consistently well in this section.

Master the must-know lists: vitamins and diseases, SI units, common acids and bases, parts of the cell, endocrine glands and their hormones. These appear in every exam cycle with minor variations.

Key Concepts

• **Physics is about motion, energy and forces**: Understand the behaviour of objects (Newton's laws), energy transformations (potential to kinetic), properties of light (reflection, refraction) and electricity basics (current, resistance, conductors vs insulators).

• **Chemistry deals with matter and its transformations**: Focus on atomic structure (protons, neutrons, electrons), the periodic table layout, chemical reactions (synthesis, decomposition), and properties of common substances like acids (pH < 7, turn litmus red), bases (pH > 7, slippery feel) and salts.

• **Biology covers living systems**: The cell is the basic unit of life. Know major organelles (nucleus holds DNA, mitochondria produce energy, chloroplasts do photosynthesis in plants). Human body systems — digestive, respiratory, circulatory, nervous — and their main organs appear frequently.

• **Nutrition and deficiency diseases**: Vitamins (A, B-complex, C, D, E, K) and minerals (iron, calcium, iodine) each have specific roles and deficiency symptoms. For example, Vitamin C deficiency causes scurvy, iodine deficiency causes goitre.

• **Everyday applications connect theory to life**: Rusting is oxidation of iron, a mirror uses reflection, a lens in spectacles uses refraction, vaccines use weakened pathogens to build immunity, and pasteurisation kills bacteria in milk by heating.

• **Measurement matters**: SI units are standard — metre (length), kilogram (mass), second (time), ampere (current), kelvin (temperature), mole (amount of substance), candela (luminous intensity). Know conversions: 1 km = 1000 m, 1 kg = 1000 g.