Most Important Question Of Physics
UNIT: Modern Physics
Lesson 1: Electrons & Protons
⚫Why electric discharge does not take place at very low pressure? (Take place at low pressure)
⚫Gases are insulator at ordinary pressure and start conducting at low pressure. Why?
⚫ The value of e/m is constant for cathode ray but not for positive ray? (Cathode ray are not electromagnetic ray. Why?)
⚫ Define: threshold frequency, stopping potential photoelectric effect, quantization of charge, cathode ray,
⚫ Millikan's oil drop experiment, JJ Thompson's experiment, Millikan's experiment to determine plank's constant, Einstein's photoelectric equation
⚫Numerical related to Millikan's experiment and photoelectric equation
Lesson 2: solids and semiconductor device
⚫ Define: Hole in semiconductors, nanotechnology, doping, truth table, logic gates, junction diode, rectifier, PN junction, Zener diode, transistor
⚫Working of full wave rectifier (figure) • Describe the formation of potential barrier and depletion region in PN junction
⚫Explain the biasing of junction diode Logic gates; NOT, OR, AND, NAND and NOR
⚫How is Zener diode is used as voltage regulator?
Lesson 3: Quantization of Energy
⚫AN electron and a proton have a same KE /speed/ potential difference. Which one of them has longer de Broglie wavelength.
⚫ State and explain Bragg's law
⚫ Define: population inversion, optical pumping, ionization energy, ionization potential, X-ray, matter wave
⚫Uncertainly principle
⚫Production of X-ray
⚫ Bohr's postulate and total energy and radius of electron in nth orbit of H
⚫ State and explain uncertainty principle
⚫ Numerical based on Bragg's law and de Broglie wavelength
Lesson: 4 Radioactivity
Lesson Recent Trends in Physics
⚫ explain the origin of earthquakes
⚫Explain different types of internal waves: S and P-waves
Unit: Mechanics
Lesson 1: Rotational dynamics
⚫Derive the expression for rotational kinetic energy
⚫Describe the term moment of inertia and radius of gyration
⚫Find the moment of inertia of thin uniform rod rotating about its center and its one end
⚫ Establish the relation between torque and angular acceleration of a rigid body • Describe the work and power in rotational motion with expression
⚫ Define angular momentum and prove the principle of conservation of angular
momentum
⚫ Solve numerical problems and conceptual questions regarding the rotational dynamics
Lesson 2: Periodic Motion
⚫Define simple harmonic motion and state its equation.
⚫Derive the expressions for energy in simple harmonic motion Derive the expression for period for vertical oscillation of a mass suspended from coiled spring
⚫ Describe angular simple harmonic motion and find its period
⚫ Derive expression for period of simple pendulum
Lesson 3: Fluid Statics
⚫State and explain Archimedes principle and Pascal's law Define up-thrust, pressure in fluid, buoyancy, center of buoyancy and meta center
⚫State and use the law of floatation,
⚫Describe surface tension and explain its principle
⚫Establish the relation between surface energy and surface tension
⚫Define angle of contact and capillarity with examples
⚫State the Newton's Formula for viscosity of a liquid and define coefficient of viscosity
⚫Differentiate between laminar and turbulent flow & describe Reynolds number
⚫ Recall and use the Poiseuille's formula
⚫State Stoke's law and use it to determine the coefficient of viscosity of given liquid
⚫Explain equation of continuity and its application
⚫Recall the Bernoulli's equation and explain its uses
⚫ Solve the Numerical problems and conceptual questions regarding the fluid Statics.
Unit: Heat and Thermodynamics
Lesson 1: First Law of Thermodynamics
⚫ Define thermodynamic system, work done by the system, work done on the system, concept of latent heat and internal energy.
⚫ State and explain first law of thermodynamics limitations and necessity of second law of thermodynamics
⚫Define and explain two specific heat capacities of gas appreciating the relation Cp-Cv=R and Cp-Cv=r.
⚫ Explain various thermodynamic process (isothermal, isobaric, sochoric and adiabatic) with good concept of their P-V diagram.
⚫Derive adiabatic equation PV^y=Constant.
⚫Drive expression for work done during isothermal and adiabatic process. Give concept of neversible and irreversible process with examples.
⚫Solve mathematical problems related to first lave of thermodynamics and thermodynamic process
Lesson 2: Second Law of Thermodynamics
⚫State and explain second law of thermodynamics (Kevin's and Clausius's
statement).
⚫ Explain heat engine as a device to convert heat energy into mechanical energy appreciating that its efficiency is less than 100%.
⚫ Discuss Carnot's cycle with the concept of P-V diagram and calculate the work
done of each step and corresponding efficiency.
⚫Describe internal combustion engines, Otto engine and diesel engine with the help of P-V diagram to compare their efficiencies.
⚫Explain refrigerator as heat engine working in reverse direction
⚫Introduce entropy as a measure of disorder appreciating its roles in thermodynamic process.
⚫Solve mathematical problems related to heat engine.
