NSEP Physics: CBSE Class 11–12 Syllabus with Olympiad Reasoning
NSEP Physics is an objective Olympiad-style screening test built on the CBSE Class 11–12 syllabus, but it rewards deeper reasoning than board-level recall. Expect mechanics, electromagnetism, optics, thermodynamics, waves, and modern physics, with numerical answers and concept traps rather than routine formula substitution. The exam is delivered in English and assumes fluency with SI units, graphs, and vector notation.
Core rules and concepts
- Mechanics: resolve forces along and perpendicular to motion; use conservation laws when non-conservative work is zero. For rotation, distinguish pure rolling (v = ωR) from slipping.
- Electromagnetism: apply Kirchhoff's laws with sign conventions, use Gauss's law for symmetric charge distributions, and relate induced emf to flux change (Faraday–Lenz).
- Optics: use the Cartesian sign convention consistently; thin-lens and mirror formulae are approximations for paraxial rays.
- Thermodynamics: identify the process (isothermal, adiabatic, isobaric, isochoric) before using PV relations; the first-law sign convention is work done by the gas positive in many texts.
- Modern physics: photon energy E = hc/λ, work function, de Broglie wavelength, and nuclear binding energy.
Worked example
A solid sphere rolls without slipping down a rough incline. What fraction of its total kinetic energy is rotational? For a solid sphere I = 2/5 MR². Rolling gives v = ωR. Total K = ½Mv² + ½Iω² = ½Mv² + ½(2/5 MR²)(v²/R²) = (7/10)Mv². Rotational K = ½Iω² = (1/5)Mv². Fraction = (1/5)/(7/10) = 2/7. The roughness does no net work when rolling is pure, so mechanical energy is conserved.
Traps that cost marks
- Using v = ωR when the body slips.
- Mixing degrees and radians in ω, or forgetting SI conversion.
- Sign errors in lens/mirror formulae and in thermodynamic work.
- Ignoring internal resistance or treating an ammeter as ideal.
- Choosing a formula without checking its assumptions (massless pulley, ideal gas, paraxial rays).