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Physics (SSC, Railway, Police & All State exam)Chapter Unit

Miscellaneous

TopicDescriptionFormula / Key Concept
Work-Energy TheoremStates that the work done on an object is equal to the change in its kinetic energy.W=ΔKE=12m(v2u2)W = \Delta KE = \frac{1}{2}m(v^2 - u^2) where vv is final velocity, uu is initial velocity, mm is mass.
Conservation of EnergyEnergy cannot be created or destroyed, only transformed from one form to another.Etotal=Kinetic Energy+Potential EnergyE_{\text{total}} = \text{Kinetic Energy} + \text{Potential Energy}
PowerThe rate at which work is done or energy is transferred.P=WtorP=EtP = \frac{W}{t} \quad \text{or} \quad P = \frac{E}{t} (SI Unit: Watt, W = J/s)
MomentumThe product of mass and velocity, representing the quantity of motion of an object.p=mvp = mv
ImpulseChange in momentum of an object when a force is applied over a period of time.J=FΔt=ΔpJ = F \Delta t = \Delta p
Circular MotionMotion of an object in a circular path, with constant or changing speed.ac=v2rorac=ω2ra_c = \frac{v^2}{r} \quad \text{or} \quad a_c = \omega^2 r (Centripetal acceleration, vv = velocity, rr = radius)
Gravitational ForceThe force of attraction between two masses.F=Gm1m2r2F = G \frac{m_1 m_2}{r^2} (where GG = gravitational constant = 6.674×1011N m2/kg26.674 \times 10^{-11} \, \text{N m}^2/\text{kg}^2)
PressureThe force applied per unit area on a surface.P=FAP = \frac{F}{A} (SI Unit: Pascal, Pa = N/m²)
BuoyancyThe upward force exerted by a fluid on a submerged or floating object.FB=ρfluidgVdisplacedF_B = \rho_{\text{fluid}} g V_{\text{displaced}} where ρ\rho is fluid density, gg is acceleration due to gravity, and VV is volume displaced.
Surface TensionThe force per unit length exerted along the surface of a liquid.γ=FL\gamma = \frac{F}{L} (SI Unit: N/m)
Heat TransferThe transfer of heat from a warmer object to a cooler one. Types include conduction, convection, and radiation.Conduction: Q=kA(T1T2)dQ = \frac{kA(T_1 - T_2)}{d} <br> Convection: Q=hA(T1T2)Q = hA(T_1 - T_2) <br> Radiation: P=σAT4P = \sigma A T^4
CapacitanceThe ability of a system to store charge per unit voltage.C=QVC = \frac{Q}{V} (SI Unit: Farad, F)
Magnetic FieldA field produced by moving charges or magnetic materials that exerts a force on other charges.B=μ0I2πrB = \frac{\mu_0 I}{2 \pi r} (for a long straight current-carrying wire)
Electromagnetic InductionThe process by which a changing magnetic field induces an electromotive force (EMF) in a conductor.E=dΦBdt\mathcal{E} = -\frac{d\Phi_B}{dt} (Faraday's Law)
Capacitor in Series and ParallelThe arrangement of capacitors in series or parallel affects their total capacitance.Series: 1Ctotal=1C1+1C2+\frac{1}{C_{\text{total}}} = \frac{1}{C_1} + \frac{1}{C_2} + \dots <br> Parallel: Ctotal=C1+C2+C_{\text{total}} = C_1 + C_2 + \dots
Energy Stored in CapacitorThe energy stored in a capacitor when charged by a voltage.E=12CV2E = \frac{1}{2} C V^2
Laws of ThermodynamicsThe fundamental laws governing energy and heat transfer.First Law: ΔU=QW\Delta U = Q - W <br> Second Law: Entropy of an isolated system tends to increase. <br> Third Law: As temperature approaches absolute zero, entropy approaches a minimum.
Thermodynamic CyclesA series of processes in which the system returns to its original state. Used in heat engines and refrigerators.Carnot Cycle: Efficiency = 1TcoldThot1 - \frac{T_{\text{cold}}}{T_{\text{hot}}}
Einstein’s Theory of RelativityDescribes the relationship between space, time, and gravity, especially at high velocities.E=mc2E = mc^2 (Energy-mass equivalence)
Wave-Particle DualityThe concept that every particle or quantum entity can exhibit both wave-like and particle-like properties.de Broglie Wavelength: λ=hmv\lambda = \frac{h}{mv} (where hh is Planck's constant, mm is mass, and vv is velocity)
Photoelectric EffectThe phenomenon where electrons are emitted from a material when it is exposed to light.Ephoton=hfE_{\text{photon}} = h f (where hh is Planck's constant, and ff is frequency)
Quantum MechanicsThe branch of physics dealing with phenomena at atomic and subatomic scales.Schrödinger’s Equation: itΨ=H^Ψi \hbar \frac{\partial}{\partial t} \Psi = \hat{H} \Psi
Heisenberg Uncertainty PrincipleStates that one cannot simultaneously know both the exact position and momentum of a particle.ΔxΔp2\Delta x \Delta p \geq \frac{\hbar}{2}
Young’s ModulusDescribes the elasticity of a material, representing its ability to deform under stress.Y=StressStrain=F/AΔL/LY = \frac{\text{Stress}}{\text{Strain}} = \frac{F/A}{\Delta L/L}

Recap: Key Points to Remember

  • Work-Energy Theorem: Work done on an object equals the change in its kinetic energy.
  • Capacitance: The ability of a capacitor to store charge.
  • Thermodynamics: Governs energy conservation, heat transfer, and entropy.
  • Wave-Particle Duality: Describes the nature of particles at quantum scales.
  • Photoelectric Effect: The emission of electrons from a material when illuminated by light.

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