NEET UG Preparation

Cards · 52

Coulomb's Law

Electrostatic force between two point charges: F = (1 / (4 * pi * epsilon_0)) * (|q1 * q2| / r^2). Unit: Newton (N).

Electric Field due to Point Charge

Force per unit charge at distance r: E = (1 / (4 * pi * epsilon_0)) * (q / r^2). Unit: Newton per Coulomb (N/C) or Volt per meter (V/m).

Electric Dipole Moment

Measure of separation of opposite electrical charges: p = q * (2a), directed from negative to positive. Unit: Coulomb-meter (C m).

Gauss's Law in Electrostatics

Total electric flux through a closed surface equals net enclosed charge divided by permittivity: Phi = q_in / epsilon_0. Unit of flux: N m^2/C.

Capacitance of a Parallel Plate Capacitor

Charge storing ability with plate area A and separation d: C = (epsilon_0 * A) / d. Unit: Farad (F).

Energy Stored in a Capacitor

Potential energy stored in electrostatic field: U = (1/2) * C * V^2 = Q^2 / (2C) = (1/2) * Q * V. Unit: Joule (J).

Ohm's Law and Drift Velocity

Current related to drift speed: I = n * e * A * v_d; microscopic Ohm's law: J = sigma * E. Current unit: Ampere (A).

Temperature Dependence of Resistance

Variation of resistance with temperature: R_T = R_0 * (1 + alpha * Delta_T), where alpha is the temperature coefficient. Unit of alpha: K^-1 or degree C^-1.

Biot-Savart Law

Magnetic field due to current element: dB = (mu_0 / (4 * pi)) * (I * dl * sin(theta) / r^2). Unit: Tesla (T).

Ampere's Circuital Law

Line integral of magnetic field around a closed loop: closed integral of B dot dl = mu_0 * I_enclosed. Unit: Tesla-meter (T m).

Lorentz Force

Total force on charge in combined electric and magnetic fields: F = q * (E + v x B). Unit: Newton (N).

Faraday's Law of Electromagnetic Induction

Induced electromotive force equals the negative time rate of change of magnetic flux: e = -dPhi_B / dt. Unit: Volt (V).

Self-Inductance of a Solenoid

Ratio of magnetic flux linkage to current: L = mu_0 * n^2 * A * l = (mu_0 * N^2 * A) / l. Unit: Henry (H).

Resonance Frequency in Series LCR Circuit

Frequency where inductive and capacitive reactances cancel: omega_0 = 1 / sqrt(L * C) or f_0 = 1 / (2 * pi * sqrt(L * C)). Unit: Hertz (Hz).

Snell's Law of Refraction

Ratio of sines of angles of incidence and refraction equals refractive index ratio: n1 * sin(i) = n2 * sin(r). Dimensionless.

Lens Maker's Formula

Relates focal length to curvature and refractive index: 1/f = (n - 1) * (1/R1 - 1/R2). Unit of focal length: Meter (m).

Young's Double-Slit Fringe Width

Spatial separation between consecutive bright or dark fringes: beta = (lambda * D) / d. Unit: Meter (m).

de Broglie Wavelength

Wavelength associated with a moving particle: lambda = h / p = h / (m * v) = h / sqrt(2 * m * K). Unit: Meter (m).

Einstein's Photoelectric Equation

Maximum kinetic energy of photoelectrons: K_max = h * nu - phi_0 = h * c / lambda - phi_0. Unit: Joule (J) or Electron-volt (eV).

Radioactive Decay Law

Number of undecayed nuclei at time t: N(t) = N_0 * e^(-lambda * t); Half-life T_half = 0.693 / lambda. Decay constant unit: s^-1.

Bohr's Angular Momentum Quantization

Angular momentum of an electron in a stable orbit: L = m * v * r = (n * h) / (2 * pi). Unit: J s or kg m^2/s.

Radius of nth Bohr Orbit (Hydrogen-like)

Orbital radius for atomic number Z and principal quantum number n: r_n = 0.529 * (n^2 / Z) Angstroms. Unit: Meter (m).

Energy of Electron in nth Bohr Orbit

Total mechanical energy of bound electron: E_n = -13.6 * (Z^2 / n^2) eV. Unit: Electron-volt (eV) or Joule (J).

Universal Law of Gravitation

Gravitational attraction between two masses: F = G * (m1 * m2) / r^2. Constant G = 6.674e-11 N m^2/kg^2. Unit: Newton (N).

Escape Velocity from a Planet

Minimum speed required to escape planetary gravitational field: v_e = sqrt((2 * G * M) / R) = sqrt(2 * g * R). Unit: m/s.

Hooke's Law and Young's Modulus

Stress proportional to strain within elastic limit: Y = (F / A) / (Delta_L / L). Unit: Pascal (Pa) or N/m^2.

Bernoulli's Principle

Conservation of energy along streamline in ideal fluid: P + (1/2) * rho * v^2 + rho * g * h = constant. Unit: Pascal (Pa).

Terminal Velocity in Viscous Fluid

Steady speed of falling sphere via Stokes' law: v_t = (2/9) * r^2 * (rho - sigma) * g / eta. Unit: m/s.

Stefan-Boltzmann Law

Total radiant energy emitted per unit surface area per unit time: E = sigma * T^4 (or P = e * sigma * A * T^4). Unit: W/m^2.

Wien's Displacement Law

Wavelength of peak blackbody emission inversely proportional to temperature: lambda_max * T = b (2.898e-3 m K). Unit: Meter-Kelvin (m K).

Carnot Engine Efficiency

Theoretical maximum efficiency of a heat engine: eta = 1 - (T_C / T_H) = (W / Q_H). Dimensionless.

Simple Harmonic Motion Time Period

Period of linear spring-mass oscillator: T = 2 * pi * sqrt(m / k); simple pendulum: T = 2 * pi * sqrt(L / g). Unit: Second (s).

Molarity (M)

Number of moles of solute dissolved per liter of solution: M = n_solute / V_solution(L). Unit: mol/L.

Molality (m)

Number of moles of solute per kilogram of solvent: m = n_solute / mass_solvent(kg). Unit: mol/kg.

Raoult's Law (Relative Lowering of Vapor Pressure)

For non-volatile solute: (P_0 - P_s) / P_0 = X_solute = n / (n + N). Dimensionless.

Elevation in Boiling Point

Colligative temperature increase: Delta_T_b = i * K_b * m, where i is the van 't Hoff factor. Unit: Kelvin (K) or degree C.

Depression in Freezing Point

Colligative temperature decrease: Delta_T_f = i * K_f * m, where K_f is the cryoscopic constant. Unit: Kelvin (K) or degree C.

Osmotic Pressure Formula

Pressure required to halt solvent flow across semipermeable membrane: Pi = i * C * R * T. Unit: Pascal (Pa) or atmosphere (atm).

First Law of Thermodynamics

Conservation of energy for closed thermodynamic system: Delta_U = q + w (IUPAC convention). Unit: Joule (J).

Gibbs Free Energy and Spontaneity

Criterion for spontaneity at constant T and P: Delta_G = Delta_H - T * Delta_S. Spontaneous when Delta_G < 0. Unit: J/mol.

Equilibrium Constant and Gibbs Free Energy

Relation between standard free energy and equilibrium: Delta_G_standard = -R * T * ln(K_eq) = -2.303 * R * T * log10(K_eq). Unit: J/mol.

Nernst Equation

Electrode or cell potential under non-standard conditions: E_cell = E_standard - (0.0591 / n) * log10(Q) at 298 K. Unit: Volt (V).

Kohlrausch's Law of Independent Migration

Molar conductivity at infinite dilution is sum of ionic contributions: Lambda_m_0 = nu_+ * lambda_+_0 + nu_- * lambda_-_0. Unit: S cm^2/mol.

Arrhenius Equation

Temperature dependence of reaction rate constant: k = A * e^(-E_a / (R * T)) or ln(k2/k1) = (E_a/R) * (1/T1 - 1/T2). E_a unit: J/mol.

Rate Constant for First-Order Reaction

Rate dependence on concentration: k = (2.303 / t) * log10([A]_0 / [A]_t); Half-life t_half = 0.693 / k. Unit: s^-1.

pH and Henderson-Hasselbalch Equation

pH of acidic buffer solution: pH = pK_a + log10([Conjugate Base] / [Weak Acid]); pH = -log10[H+]. Dimensionless.

Heisenberg's Uncertainty Principle

Fundamental limit on precision of position and momentum: Delta_x * Delta_p >= h / (4 * pi). Unit: J s or kg m^2/s.

Hardy-Weinberg Equilibrium Principle

Allele and genotype frequencies remain constant across generations without evolutionary forces: p^2 + 2pq + q^2 = 1. Dimensionless.

Cardiac Output Formula

Volume of blood pumped by each ventricle per minute: Cardiac Output = Stroke Volume * Heart Rate (approx 70 mL * 72 bpm = 5 L/min). Unit: L/min.

Glomerular Filtration Rate (GFR)

Volume of filtrate formed by kidneys per minute: GFR approx 125 mL/min (180 L/day) in healthy human. Unit: mL/min.

Photosynthetic Net Assimilation / Water-Splitting

Photolysis in Photosystem II: 2H2O -> 4H+ + 4e- + O2; produces reducing power (NADPH) and ATP for Calvin cycle. Dimensionless stoichiometry.

Respiratory Quotient (RQ)

Volume ratio of CO2 produced to O2 consumed: RQ = V(CO2) / V(O2). RQ = 1.0 for carbohydrates, 0.7 for fats, 0.9 for proteins. Dimensionless.