Drawbacks of Old Quantum Theory

Planck's quantum hypothesis with its application and extension to explain the black body radiation like the photo-electric effect, the Compton effect, the variation of specific heat of solid with temperature and the spectrum of hydrogen is now called the Old quantum theory. Through these phenomena are successfully explained by the theory, there are numerous drawbacks of the theory. A few of them are as follows.

1.) Bohr's quantization rules are arbitrary. The theory does not provide a physical explanation for the assumptions.

2.) The old quantum theory cannot be applied to explain the spectra of helium and of more complex atoms.

3.) It can provide only a qualitative and incomplete explanation of the intensities of the spectral lines.

4.) It can not explain the dispersion of light.

5.) The theory of non-harmonic vibrations of systems cannot be applied to explain the vibrations of systems.

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  • Comparison between electric charge and mass

  • Coulomb′s law and Application

  • Vector form of Coulomb′s Law

  • Force between multiple charges (Superposition principle of electrostatic forces)

  • Electric Line of Force and its Properties

  • Electric field Intensity (Definition) and Electric field Intensity due to point charge

  • Electric Dipole and Derivation of Electric field intensity at different points of an electric dipole

  • Derivation of torque on an electric dipole in an uniform and a non-uniform electric field


  • Electric potential and derivation of electric potential at a point due to point charged particle

  • Work done by a rotating electric dipole in uniform electric field

  • The electric potential at different points of the electric dipole

  • The electric potential energy of an electric dipole in the uniform electric field

  • The electric potential energy of a system of Charges


  • Gaussian Surface and its Properties

  • Gauss's Law for Electric Flux and Derivation

  • Electric field intensity due to point charge by Gauss's Law

  • Electric field Intensity due to a uniformly charged Spherical Shell

  • Electric field intensity due to the uniformly charged solid sphere(Conducting and Non-conducting)

  • Electric field intensity due to thick hollow non-conducting sphere

  • Electric field intensity due to uniformly charged plane sheet and parallel sheet

  • Electric field intensity due to uniformly charged wire of infinite length


  • Capacitance of an Isolated Spherical Conductor

  • Potential Energy of a Charged Conductor

  • Parallel Plate Air Capacitor and Its Capacitance

  • Capacitance of a Parallel Plate Capacitor Partly Filled with Dielectric Slab between Plates

  • Force between the plates of a Charged Parallel Plate Capacitor

  • Energy Stored in a Charged Capacitor



  • Description dielectric materials and their types



  • Combination of cell in the circuit

  • Relation between electromotive force (E), internal resistance (r) and potential difference (V) in a circuit

  • Relation between electric current and drift velocity

  • Derivation of Ohm's Law

  • Kirchhoff's laws for an electric circuits

  • Wheatstone's Bridge

  • Metre Bridge OR Slide Wire Bridge

  • Principle construction and working of potentiometer

  • Difference between Potentiometer and Voltmeter



  • Biot- Savart's Law

  • Motion of Charged Particles in Uniform Magnetic Field

  • Magnetic Field due to a Straight Current-Carrying Conductor of Finite Length

  • Ampere's circuital Law and its modification

  • Magnetic Field at the axis of a current-carrying circular loop

  • Magnetic Field at the center of a current-carrying circular loop

  • Principle, Construction and Working of Current Carrying Solenoid

  • Derivation of force on current carrying conductor in uniform magnetic field

  • Derivation of Force between two long and parallel current-carrying conductors



  • Magnetic Dipole Moment of Current carrying loop

  • Magnetic potential energy of current-loop in a magnetic field

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  • Conversion of Galvanometer into an Ammeter

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  • Diamagnetic substances and its properties

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  • Mean Value and Root Mean Square Value of Alternating Current

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  • Alternating Current Circuit containing Inductance only (L-Circuit)

  • Alternating Current Circuit containing Capacitance only (C-Circuit)

  • Circuit containing Inductor and Resistor in Series (L-R Series Circuit )

  • Circuit containing Capacitor and Resistor in Series (C-R Series Circuit )

  • Circuit containing Inductor and Capacitor in Series (L-C Series Circuit )

  • Circuit containing Inductor, Capacitor, and Resistor in Series (L-C-R Series Circuit )

  • Power in Alternating Current Circuit

  • Merits and Demerits of Alternating Current in Comparison to Direct Current



  • Faraday's Laws of Electromagnetic Induction

  • Self Induction and its Coefficient

  • Mutual Induction and its Coefficient



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  • Inadequacy of classical mechanics

  • Drawbacks of Old Quantum Theory

  • Bohr's Quantization Condition

  • Energy distribution spectrum of black body radiation

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  • Davisson and Germer's Experiment and Verification of the de-Broglie Relation

  • Significance of Compton's Effect

  • Assumptions of Planck’s Radiation Law

  • Derivation of Planck's Radiation Law

  • de-Broglie Concept of Matter wave

  • Definition and derivation of the phase velocity and group velocity of wave

  • Relation between group velocity and phase velocity ($V_{g}=V_{p}-\lambda \frac{dV_{p}}{d\lambda }$)

  • Group velocity is equal to particle velocity($V_{g}=v$)

  • Product of phase velocity and group velocity is equal to square of speed of light ($V_{p}.V_{g}=c^{2}$)

  • Heisenberg uncertainty principle

  • Generation of wave function for a free particle

  • Physical interpretation of the wave function

  • Derivation of time dependent Schrodinger wave equation

  • Derivation of time independent Schrodinger wave equation

  • Eigen Function, Eigen Values and Eigen Vectors

  • Postulate of wave mechanics or Quantum Mechanics

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  • Normalized and Orthogonal wave function

  • Particle in one dimensional box (Infinite Potential Well)

  • Minimum Energy Or Zero Point Energy of a Particle in an one dimensional potential box or Infinite Well

  • Normalization of the wave function of a particle in one dimension box or infinite potential well

  • Orthogonality of the wave functions of a particle in one dimension box or infinite potential well

  • Eigen value of the momentum of a particle in one dimension box or infinite potential well

  • Schrodinger's equation for the complex conjugate waves function

  • Probability Current Density for a free particle in Quantum Mechanics

  • Ehrenfest's Theorem and Derivation

  • Momentum wave function for a free particle

  • Wave function of a particle in free state

  • One dimensional Step Potential Barrier for a Particle



  • Overview and History of Special Relativity

  • Inertial-frame and Non-inertial frame

  • Galilean Transformation Equations and Failure of Galilean Relativity

  • Derivation of Lorentz Transformation's Equations

  • Consequences of Lorentz's Transformation Equations

  • Concept of Simultaneity in Special Relativity

  • Derivation of Addition of Velocity in Special Relativity

  • Variation of Mass with Velocity in Relativity

  • Einstein’s Mass Energy Relation Derivation



  • Nuclear Force and Its Properties

  • Weak nuclear force or interaction and its properties

  • Radioactive Decay and its types

  • Mass Defect, Binding Energy and Binding Energy per nucleon

  • Nuclear Fission and Nuclear Fusion

  • Binding Energy Curve

  • Construction and Working of Nuclear Reactor or Atomic Pile

  • Safety measures for nuclear power plants



  • Description of Force and their Types

  • Work Energy Theorem Statement and Derivation

  • Conservative force and Non Conservative force

  • Conservation Law of linear momentum and its Derivation

  • Relation between angular velocity and linear velocity

  • Relation between angular acceleration and linear acceleration

  • Definition and Derivation of Centripetal Acceleration

  • Definition and Practical Applications of Centripetal Force

  • Motion of body in a vertical circle and its Practical Applications

  • Principle and Proof of Law of Conservation of Energy

  • Definition of work done and its essential condition

  • Force of Friction | Expression for the acceleration and the work done on inclined rough surface| Advantage and Disadvantage



  • Kepler's Laws of Planetary Motion

  • Newton's law for Gravitational Force

  • Deduction of Newton's Law of gravitation from Kepler's Law

  • Relation between gravitational acceleration and gravitational force

  • Gravitational field, Intensity of Gravitational field and its expression

  • Derivation of Gravitational Potential due to Point mass and on the Earth

  • Derivation of Gravitational Potential Energy due to Point mass and on the Earth

  • Expression for Orbital velocity of Satellite and Time Period

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  • Displacement Current

  • Derivation of Maxwell first equation

  • Derivation of Maxwell's second equation

  • Derivation of Maxwell's third equation

  • Derivation of Maxwell's forth equation

  • Equation of continuity of electromagnetic wave

  • Equation of continuity for current density

  • Electromagnetic wave equation in free space

  • Solution of electromagnetic wave equations in free space

  • Transverse nature of electromagnetic waves

  • Electric and magnetic field vector are mutually perpendicular to each other in electromagnetic wave

  • Electromagnetic wave equation in non conducting media (i.e. Perfect dielectric or Lossless media)

  • Solution of electromagnetic wave equations in non conducting media

  • Electromagnetic Wave Equation in Conducting Media (i.e. Lossy dielectric or Partially Conducting)

  • Solution of electromagnetic wave equations in conducting media

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  • Poynting Vector and Poynting Theorem

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  • Laser and properties of a Laser beam

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  • Population of energy level and it thermal equilibrium condition

  • Absorption, Spontaneous Emission and Stimulated Emission of Radiation

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  • Three level pumping in Laser

  • Four level pumping in Laser

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  • Refraction of light and its Properties

  • Refraction of light through concave spherical surface

  • Refraction of light through convex spherical surface

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  • Combined focal length and power of two thin lenses in contact



  • Principle Construction, Working and Angular Magnification of Simple Microscope

  • Principle Construction, Working and Angular Magnification of Compound Microscope



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  • Interference of light due to a wedge shaped thin film

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  • Fraunhofer diffraction due to a double slit

  • Missing Order in double slit diffraction pattern

  • Diffraction due to a plane diffraction grating or N- Parallel slits

  • Dispersive power of plane diffraction grating and its expression

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  • Comparison of Step Index and Graded Index Fibres

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  • Fluid and it's important characteristics

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  • Viscosity, Viscous force and Coefficient of Viscosity



  • Difference between sound waves and light waves

  • Difference between Natural (Free) Vibrations and Forced Vibrations

  • Difference between Natural Vibrations and Damped Vibrations

  • Difference between Forced Vibrations and Resonant Vibrations

  • Intensity of a wave



  • Bohr's Model of Atom

  • Bohr's Theory of Hydrogen-Like Atoms

  • Limitations of Bohr's Model

  • Spectrum of Hydrogen Atom



  • Laws of Photoelectric Emission

  • Failure of wave theory in explaining photoelectric emission effect

  • Einstein Photoelectric Emission



  • Basics and types of nanomaterials

  • Synthesis of Nanomaterials

  • Preparation of Nanostructured Particles By Sol-Gel Method

  • Nanoparticles and Its Properties



  • Difference between Heat and Temperature

  • Difference between Heat Capacity and Specific Heat Capacity

  • Comparison of Isothermal and Adiabatic Processes for an Ideal Gas



  • Concept of Perfect Gas

  • Kinetic theory of ideal gases



  • Superconductor and its properties



  • Origin of Biomedical Signals



  • Basics of Semiconductor Materials

  • Basics of Third Generation Solar Cells and Their Types



  • Renewable Energy Sources



  • Limitations of Dimensional Analysis

  • Description of Errors in Measurement

  • Finding Significant Figures in a Measurement


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