JIPMER Entrance Physics Syllabus

Define stress, strain, and Young's modulus.

Stress = force/area (N/m²); Strain = change in dimension/original dimension (dimensionless); Young's modulus Y = longitudinal stress/longitudinal strain.

State Hooke's law and define the elastic limit.

Within the elastic limit, stress is directly proportional to strain (stress = E x strain). The elastic limit is the maximum stress up to which a body returns to its original shape on removing the load.

What is the elastic potential energy stored per unit volume in a stretched wire?

Energy per unit volume = ½ x stress x strain = ½ x Y x strain². Total energy = ½ x stress x strain x volume.

State Pascal's law and give a practical application.

Pressure applied to an enclosed fluid is transmitted undiminished to every part of the fluid and the container walls. Application: hydraulic lift/brakes (force multiplication).

State Archimedes' principle and the condition for floating.

A body immersed in a fluid experiences an upward buoyant force equal to the weight of the fluid displaced. A body floats when its weight equals the buoyant force (avg density ≤ fluid density).

State Bernoulli's theorem.

For ideal (non-viscous, incompressible, streamline) flow, P + ½ρv² + ρgh = constant along a streamline (sum of pressure, kinetic, and potential energy per unit volume is conserved).

State the equation of continuity for fluid flow.

For an incompressible fluid, A₁v₁ = A₂v₂ (mass flow rate Av = constant); narrower cross-section means higher velocity.

Define coefficient of linear, areal, and volume expansion and their relation.

α (linear), β (areal), γ (volume) give fractional change per unit temperature rise. For isotropic solids: β = 2α and γ = 3α.

Define specific heat capacity and latent heat. State the principle of calorimetry.

Specific heat: heat to raise 1 kg by 1 K (Q = mcΔT). Latent heat: heat to change phase without temperature change (Q = mL). Calorimetry: heat lost by hot body = heat gained by cold body.

State the first law of thermodynamics.

ΔQ = ΔU + ΔW: heat supplied to a system equals the increase in internal energy plus the work done by the system. It is the law of conservation of energy.

Compare isothermal and adiabatic processes.

Isothermal: T constant, ΔU = 0, PV = constant, occurs slowly. Adiabatic: Q = 0, PV^γ = constant, internal energy changes, occurs quickly. Adiabatic curve is steeper on a PV diagram.

State the second law of thermodynamics (Kelvin-Planck and Clausius statements).

Kelvin-Planck: no engine can convert all absorbed heat into work with no other effect. Clausius: heat cannot flow spontaneously from a colder to a hotter body.

What is the efficiency of a Carnot engine and the coefficient of performance of a refrigerator?

Carnot efficiency η = 1 - T_cold/T_hot. Refrigerator COP = T_cold/(T_hot - T_cold). Temperatures must be in kelvin.

State the postulates and key result of the kinetic theory of gases for pressure.

Gas consists of tiny molecules in random motion with elastic collisions and negligible volume. Pressure P = (1/3)ρ<v²> = (1/3)(N/V)m<v²>.

Give the relation between temperature and average kinetic energy, and the law of equipartition of energy.

Average translational KE per molecule = (3/2)k_B T. Equipartition: each degree of freedom contributes (1/2)k_B T of energy per molecule.

Define rms, average, and most probable speeds of gas molecules and their ratio.

v_rms = √(3RT/M), v_avg = √(8RT/πM), v_mp = √(2RT/M). Ratio v_mp : v_avg : v_rms = 1 : 1.128 : 1.224.

Compare conduction, convection, and radiation.

Conduction: heat transfer through matter without bulk movement (solids). Convection: transfer by actual movement of fluid (liquids/gases). Radiation: transfer by electromagnetic waves, needs no medium.

State Stefan-Boltzmann law and Wien's displacement law.

Stefan-Boltzmann: E = σT⁴ (power radiated per unit area of a black body, σ = 5.67x10^-8 W/m²K⁴). Wien: λ_max T = b = 2.9x10^-3 m·K (peak wavelength shifts to shorter λ as T rises).

State Newton's law of cooling.

The rate of cooling of a body is directly proportional to the temperature difference between the body and its surroundings (for small differences): dT/dt ∝ (T - T_surroundings).

Define simple harmonic motion and give the equation for its restoring force and time period.

SHM: motion where restoring force is proportional to displacement and directed toward the mean position, F = -kx. Time period T = 2π√(m/k); a = -ω²x.

Give the time periods of a simple pendulum and a spring-mass system.

Simple pendulum: T = 2π√(L/g). Spring-mass: T = 2π√(m/k). Pendulum is independent of mass; spring is independent of g.

Write the expressions for velocity and acceleration in SHM and where they are maximum.

v = ω√(A² - x²), maximum (ωA) at mean position. a = -ω²x, maximum (ω²A) at extreme positions. KE max at center, PE max at extremes.

Give the relation between wave speed, frequency, and wavelength, and the speed of a wave on a string.

v = fλ. On a stretched string, v = √(T/μ), where T is tension and μ is mass per unit length.

State the principle of superposition and define constructive/destructive interference.

When two waves overlap, the resultant displacement is the vector sum of individual displacements. Constructive: path difference = nλ (in phase); Destructive: path difference = (n+½)λ (out of phase).

Distinguish standing waves' nodes and antinodes; give frequencies of a string fixed at both ends.

Nodes: zero displacement; Antinodes: maximum displacement. For a string of length L fixed at both ends, f_n = nv/2L (n = 1,2,3...), the fundamental at n=1.

What factors affect the speed of sound, and what is the Doppler effect?

Speed of sound increases with temperature (v ∝ √T) and is greatest in solids > liquids > gases. Doppler effect: apparent change in frequency due to relative motion between source and observer.

Write the Doppler effect formula for the observed frequency of sound.

f' = f (v ± v_o)/(v ∓ v_s), where v is sound speed, v_o observer speed, v_s source speed. Signs chosen so approaching raises and receding lowers the frequency.

State Coulomb's law and the value of the constant.

F = k q₁q₂/r², along the line joining the charges. k = 1/(4πε₀) ≈ 9 x 10⁹ N·m²/C²; ε₀ = 8.85 x 10^-12 C²/N·m².

State Gauss's law and define electric flux.

Electric flux Φ = E·A. Gauss's law: the net flux through a closed surface equals q_enclosed/ε₀. Used to find fields of symmetric charge distributions.

Give the capacitance of a parallel-plate capacitor and energy stored in a capacitor.

C = ε₀A/d (with dielectric, C = Kε₀A/d). Energy stored U = ½CV² = ½QV = Q²/2C.

State Ohm's law and give the formula for resistance in terms of resistivity.

V = IR at constant temperature. R = ρL/A, where ρ is resistivity, L is length, A is cross-sectional area; resistance increases with temperature for metals.

Give the equivalent resistance for resistors in series and parallel.

Series: R_eq = R₁ + R₂ + ...; Parallel: 1/R_eq = 1/R₁ + 1/R₂ + ... Parallel combination has resistance less than the smallest resistor.

State Kirchhoff's two laws.

Junction (current) law: sum of currents entering a junction = sum leaving (charge conservation). Loop (voltage) law: sum of EMFs and potential drops around a closed loop = 0 (energy conservation).

State the right-hand rule and the Biot-Savart law for magnetic field.

Right-hand rule: thumb points along current, curled fingers give field direction. Biot-Savart: dB = (μ₀/4π)(I dl sinθ)/r²; field of a long straight wire B = μ₀I/2πr.

Give the force on a current-carrying conductor and on a moving charge in a magnetic field.

On conductor: F = BIL sinθ. On a moving charge: F = qvB sinθ (Lorentz force F = q(E + v x B)); the magnetic force is perpendicular to velocity, so it does no work.

State Faraday's laws of electromagnetic induction and Lenz's law.

Induced EMF = -dΦ/dt (rate of change of magnetic flux); EMF magnitude proportional to rate of flux change. Lenz's law: induced current opposes the change causing it (energy conservation); the minus sign expresses this.

Define self-inductance and mutual inductance.

Self-inductance L: EMF induced in a coil due to change in its own current, ε = -L dI/dt. Mutual inductance M: EMF in one coil due to changing current in a neighboring coil, ε₂ = -M dI₁/dt.

In AC, define rms value and give the relation to peak value; state the resonance condition for an LCR circuit.

I_rms = I_peak/√2, V_rms = V_peak/√2. Resonance occurs when X_L = X_C, i.e. ω = 1/√(LC); impedance is minimum and current is maximum.

Define inductive and capacitive reactance and impedance of a series LCR circuit.

X_L = ωL, X_C = 1/ωC. Impedance Z = √(R² + (X_L - X_C)²); power factor cosφ = R/Z.

List the electromagnetic spectrum in order of increasing frequency and give the speed of EM waves.

Radio < microwave < infrared < visible < ultraviolet < X-rays < gamma rays. All travel at c = 3 x 10⁸ m/s in vacuum; c = 1/√(μ₀ε₀).

State the laws of reflection and the mirror formula.

Angle of incidence = angle of reflection; incident ray, reflected ray, and normal lie in one plane. Mirror formula: 1/v + 1/u = 1/f; magnification m = -v/u.

State Snell's law and define critical angle and total internal reflection.

n₁ sinθ₁ = n₂ sinθ₂. Critical angle θ_c: sinθ_c = 1/n; for incidence beyond θ_c (going to a rarer medium), light undergoes total internal reflection.

Give the lens maker's formula and the formula for power of a lens.

Lens maker's: 1/f = (n-1)(1/R₁ - 1/R₂). Lens formula: 1/v - 1/u = 1/f. Power P = 1/f (in metres), unit dioptre (D); powers add for lenses in contact.

State the condition for fringe formation in Young's double-slit experiment and the fringe width.

Bright fringes: path difference = nλ; dark fringes: (n+½)λ. Fringe width β = λD/d, where D is slit-to-screen distance and d is slit separation.

What is the difference between interference and diffraction?

Interference: superposition of waves from two (or more) coherent sources, giving equally spaced fringes of uniform intensity. Diffraction: bending of light around an obstacle/slit from secondary wavelets of a single source, giving unequal fringes with a bright central maximum.

Define polarization and state Brewster's law.

Polarization restricts light vibrations to one plane, proving light is transverse. Brewster's law: tan i_p = n, where i_p is the polarizing angle; reflected and refracted rays are perpendicular at this angle.

State Einstein's photoelectric equation and define work function.

KE_max = hf - φ₀, where φ₀ is the work function (minimum energy to eject an electron). Stopping potential V₀: eV₀ = hf - φ₀; threshold frequency f₀ = φ₀/h.

State the de Broglie hypothesis and give the wavelength formula.

Matter has wave nature; a particle of momentum p has wavelength λ = h/p = h/mv. For an electron accelerated through V: λ = 12.27/√V Å.

State the key observations of the photoelectric effect that classical physics could not explain.

Emission is instantaneous; max KE depends on frequency not intensity; below threshold frequency no emission occurs regardless of intensity; current (number of electrons) depends on intensity.

State Bohr's postulates for the hydrogen atom.

Electrons orbit in stationary states without radiating; angular momentum is quantized, L = nh/2π; energy is emitted/absorbed only when an electron jumps between orbits, hf = E_2 - E_1.

Give the energy of the nth Bohr orbit of hydrogen and the radius of the first orbit.

E_n = -13.6/n² eV (ground state -13.6 eV). Radius r_n = 0.529 n² Å; first Bohr radius = 0.529 Å. Energy increases (less negative) with n.

Write the Rydberg formula for the hydrogen spectrum and name the visible series.

1/λ = R(1/n₁² - 1/n₂²), R = 1.097 x 10⁷ m⁻¹. The Balmer series (transitions to n=2) lies in the visible region; Lyman (n=1) is UV, Paschen (n=3) is IR.

Define mass defect and binding energy of a nucleus.

Mass defect Δm = (sum of nucleon masses) - (actual nuclear mass). Binding energy = Δm·c² (1 u = 931.5 MeV); higher binding energy per nucleon means a more stable nucleus (peak near iron).

Compare alpha, beta, and gamma radiation.

Alpha: helium nucleus (²₄He), +2 charge, least penetrating, most ionizing. Beta: electron/positron, -1/+1 charge, moderate penetration. Gamma: high-energy photon, no charge, most penetrating, least ionizing.

State the law of radioactive decay and define half-life.

N = N₀e^(-λt); activity ∝ number of nuclei. Half-life T½ = ln2/λ = 0.693/λ is the time for half the nuclei to decay; mean life τ = 1/λ = T½/0.693.

Distinguish nuclear fission from nuclear fusion.

Fission: a heavy nucleus splits into lighter nuclei releasing energy (e.g. U-235 in reactors). Fusion: light nuclei combine into a heavier nucleus releasing energy (e.g. in the Sun); fusion releases more energy per nucleon.

Distinguish intrinsic from extrinsic semiconductors and define n-type and p-type doping.

Intrinsic: pure semiconductor (Si, Ge) with equal electrons and holes. Extrinsic: doped. n-type: doped with pentavalent (donor) impurity, electrons majority carriers. p-type: doped with trivalent (acceptor) impurity, holes majority carriers.

Explain the working of a p-n junction diode under forward and reverse bias.

Forward bias (p to +): depletion layer narrows, diode conducts (low resistance). Reverse bias (p to -): depletion layer widens, only tiny leakage current flows (high resistance). Acts as a one-way valve.

What is a rectifier, and how does a full-wave rectifier differ from a half-wave rectifier?

A rectifier converts AC to DC using diodes. Half-wave uses one diode and conducts for half the cycle; full-wave (two diodes or bridge of four) conducts both halves, giving higher efficiency and lower ripple.