PCM (Paper-II): Physics, Chemistry and Mathematics
OSSTET Paper-II PCM assesses Physics, Chemistry and Mathematics at secondary level. Questions reward correct formulae, unit discipline and the ability to choose the shortest valid method.
Core rules and concepts
- Physics: SI units and dimensions; Newton’s laws; work–energy theorem; Ohm’s law and series/parallel circuits; reflection/refraction and lens formula; sign conventions.
- Chemistry: mole concept and stoichiometry; periodic trends; chemical equilibrium and Le Chatelier; acids/bases and pH; functional groups and basic organic reactions.
- Mathematics: algebraic identities; trigonometric ratios and identities; differentiation/integration; matrices and determinants; probability; domain restrictions.
Worked example
Find and classify the stationary points of f(x) = x³ − 3x. Differentiate: f′(x) = 3x² − 3 = 3(x − 1)(x + 1), so stationary points are x = 1 and x = −1. Second derivative f″(x) = 6x: at x = 1, f″ > 0, so local minimum; at x = −1, f″ < 0, so local maximum. Reasoning: stationary points come from f′ = 0; the sign of f″ decides concavity, not the value of f.
Traps that cost marks
Omitting units in physics; using the wrong sign convention for mirrors/lenses; failing to identify the limiting reagent; forgetting to balance charges; cancelling expressions that may be zero; mixing rows and columns in matrix multiplication; ignoring domain restrictions in trigonometry and logarithms.