Physics Mid Exam Syllabus (Units 1–6): Properties of Matter to Engineering Materials: 30 flashcards

For small deformations, stress is directly proportional to strain: stress ∝ strain, or stress = E × strain, where E is the modulus of elasticity.

Stress is the internal restoring force per unit area set up inside a deformed body. SI unit: pascal (Pa) or N/m².

Strain is the fractional change in dimension (change in length ÷ original length). It is a dimensionless ratio with no unit.

Young's modulus Y is the ratio of longitudinal stress to longitudinal strain within the elastic limit: Y = (F/A) ÷ (ΔL/L).

A beam clamped at one end and loaded at the free end bends down by δ = Wl³/(3YI). Measuring δ, load W, length l and moment of inertia I gives Y.

Bending in which the beam curves into a circular arc of large radius, so the bending moment varies along the length; used to find Y from the depression of a centrally loaded beam.

Bending in which the beam is bent into a circular arc of constant curvature by equal and opposite couples at the ends, so the bending moment is the same everywhere.

The I-shape places most material in the flanges far from the neutral axis, increasing the moment of inertia and hence the beam's resistance to bending for the same mass of material.

It is the restoring torque per unit angle of twist, C = πηr⁴/(2l), where η is the rigidity modulus, r the wire radius and l its length.

The time period is T = 2π√(I/C). Measuring T and the moment of inertia I gives C, and from C = πηr⁴/(2l) the rigidity modulus η is calculated.

Oscillatory motion in which the restoring force (or acceleration) is directly proportional to displacement from the mean position and always directed towards it: F = −kx.

Oscillation in which a resistive force (often proportional to velocity) removes energy, so the amplitude decreases exponentially with time while the period stays nearly constant.

Blackbody radiation, the photoelectric effect, and the Compton effect — each could not be explained by classical wave theory and required quantum ideas.

Energy is emitted or absorbed in discrete quanta E = hν, where h is Planck's constant and ν the frequency; this gave the correct energy distribution function.

Every moving particle has an associated matter wave of wavelength λ = h/p = h/(mv), linking particle momentum to wave behaviour.

Electrons diffracted from a nickel crystal, producing a diffraction pattern that confirmed the wave nature of electrons and the de Broglie relation.

Position and momentum (or energy and time) cannot both be known with unlimited precision: Δx·Δp ≥ ħ/2. It is a fundamental limit, not an instrument error.

ψ describes the state of a quantum system; |ψ|² gives the probability density of finding the particle at a point. ψ must be single-valued, continuous and finite.

iħ ∂ψ/∂t = −(ħ²/2m) ∂²ψ/∂x² + Vψ, describing how the wave function evolves with time.

−(ħ²/2m) d²ψ/dx² + Vψ = Eψ, used for stationary states of constant total energy E.

A₂₁ is the probability coefficient for spontaneous emission; B₁₂ and B₂₁ are coefficients for absorption and stimulated emission. They relate emission and absorption rates in matter-radiation interaction.

Population inversion means more atoms occupy a higher energy state than a lower one. It makes stimulated emission exceed absorption, giving amplification of light — the basis of laser action.

A superconductor below its critical temperature expels all magnetic flux from its interior, acting as a perfect diamagnet (B = 0 inside).

Type I have a single critical field and expel flux completely (perfect diamagnets). Type II have two critical fields and allow partial flux penetration as vortices; they can carry higher currents and are used in strong magnets.

Group IV elements such as silicon and germanium have four valence electrons and form covalent crystals; their controlled doping produces P-type and N-type semiconductors.

P-type is doped with trivalent impurities, creating holes as majority carriers. N-type is doped with pentavalent impurities, creating electrons as majority carriers.

Unit 1 gives classical solid mechanics; Unit 2 adds oscillations; Unit 3 shows why quantum mechanics is needed; Unit 4 gives its equations; Unit 5 applies quantum energy levels to lasers; Unit 6 applies band behaviour to superconductors and semiconductors.

The Physics (BE01RR0021) mid-exam is on 29-09-2026, within the exam window of 28 September to 5 October 2026.

Computer, EC and Electrical branches.

Each unit maps to one course outcome: Unit 1→CO1, Unit 2→CO2, Unit 3→CO3, Unit 4→CO4, Unit 5→CO5, Unit 6→CO6.