About this previous year paper
This question paper covers essential topics of crystal physics, electromagnetism, dielectric behavior, magnetic properties, semiconductor physics, and superconductivity.
It is divided into three sections assessing definitions, theoretical concepts, numerical applications, and analytical explanations.
SECTION – A (7 × 2 = 14 Marks)
This section contains seven short questions, each requiring brief, precise definitions.
Topics include:
Unit cell in crystal structures
Compton effect
Polarization in dielectrics
Magnetic susceptibility
Maxwell’s displacement current
Effective mass of electrons in solids
Meissner effect in superconductors
This section tests fundamental concepts and basic understanding.
SECTION – B (3 × 7 = 21 Marks)
Students must attempt any three medium-length descriptive questions.
Topics include:
Bragg’s X-ray spectrometer and crystal structure analysis
Langevin’s theory of diamagnetism and negative susceptibility
Maxwell’s equations in free space & orthogonality of E, H, and propagation direction
Formation of energy bands; comparison of conductors, semiconductors & insulators
Buckyballs (Fullerenes): preparation, properties, applications
This section evaluates conceptual clarity, derivation skills, and theoretical reasoning.
SECTION – C (5 × 7 = 35 Marks)
Students must attempt multiple sub-questions from four groups, each covering advanced concepts and numerical problems.
Group 3 — Crystal Physics
Crystal structure of NaCl
Miller indices and method of determination
Interplanar spacing for cubic planes like (101), (112)
Group 4 — Dielectrics & Magnetism
Effect of AC electric fields on dielectric constant
Calculation of relative permittivity
Hysteresis and energy loss per cycle using B–H curve
Group 5 — Electromagnetic Theory
Equation of continuity & its significance
Poynting theorem and energy flow in EM fields
Skin depth calculation for good conductors
Group 6 — Semiconductors
Conductivity of intrinsic and extrinsic semiconductors
Fermi–Dirac distribution at different temperatures
Numerical problem on current through a semiconductor slab
Group 7 — Superconductivity
Transition temperature & effect of magnetic field
Type-I vs Type-II superconductors & magnetization curves
Numerical problem on critical magnetic field of lead
This section tests numerical ability, derivations, deeper understanding, and application of physical laws.