General Science
Core areas
Revise NCERT-level physics, chemistry and biology. Physics: SI units, motion, Newton's laws, work-energy-power, light and optics, electricity, sound. Chemistry: atomic structure, periodic table trends, acids-bases-salts, pH, formulae, metals and non-metals, common compounds. Biology: cell and tissues, human digestive, respiratory and circulatory systems, nutrition and vitamins, diseases and pathogens, plant physiology and ecology. Applied-science questions on health and technology are common.
Traps
Unit conversion is the biggest trap: 1 km/h = 5/18 m/s and 1 g/cm3 = 1000 kg/m3. In optics, real images are inverted and can be projected; virtual images are erect. In circuits, current is the same in series and voltage is the same in parallel. Deficiency diseases must be paired precisely: vitamin A with night blindness, vitamin C with scurvy, vitamin D with rickets and iron with anaemia. Do not confuse atomic number with mass number. Check whether a question asks for speed or velocity, mass or weight.
Worked example
Convert 72 km/h into m/s. Multiply by 5/18: 72 x 5/18 = 20 m/s. Rule of thumb: convert every quantity to SI units before substituting into a formula, write the unit beside the answer, and estimate whether the result is plausible.