My Physics Guide

CLASS: XII (PHYSICS) AISSCE Chapter 1: Electric charge & field State Coulomb’s law of electrostatics. What is electric field intensity? Write its S.I. unit. Draw the electric field lines for (i) q>0 (ii) q<0 (iii) two equal positive charges (iv) Electric diploe (v) Uniform electric field. What is an electric dipole? Define dipole moment. Write its S.I. unit. Derive an expression for electric field due to dipole (i) At axial point (ii) At equatorial point. Derive an expression for torque acting on dipole in an external electric field. Define electric flux. Either electric flux is a scalar or vector quantity? Write its S.I. unit. State gauss’s theorem & use it to derive an expression for electric field due to infinitely long charged straight wire of linear charge density λ. Draw the graph showing the variation of electric field with distance. Derive an expression for electric field due to a uniformly charged spherical shell of radius ‘R’ at (i) outside the sphere (r>R) a...

  Equipotential surfaces 1.  What is an equipotential surface? Show that work is done in moving a test charge from one point to another over such surface.            2.  What is the shape of equipotential surfaces for a point charge?  3. Draw an equipotential surface in a uniform electric field. 4. Two point charges + 10 µC and -10 µC are separated by a distance of 40 cm in air. a. calculate  the  electrostatic potential energy of the system, assuming the zero of the potential energy to be at infinity b. Draw an equipotential surface of the system. [ -2.25J, Perpendicular bisector] Calculate the equivalent capacitance between points A and B in the circuit below. If a battery of 10 V is connected across A and B, calculate the charge drawn from the battery by the circuit. Answer: 10 µF,  10 –4 C

  Chapter-1 ELECTRIC CHARGES AND FIELDS 1.What does q1+q2=0 signify? 2.Define electric field intensity. Give its S.I. unit. 3. Define relative permittivity OR dielectric constant of a medium? 4.What is the formula for force experienced by a charge q placed in a uniform electric field E? 5.Electric field lines can not have a sudden break. Explain. 6.Define electric dipole moment. Write its S.I. unit. 7.Is electric dipole moment is a scalar or a vector? If it is a vector, then what is its direction? 8.In which orientation, a dipole placed in a uniform electric field is in (i) Stable equilibrium (ii) unstable equilibrium? 9.Define electric flux. Write its S.I. unit. 10.Draw the electric field lines due to a point charge Q when (i) Q>0 and (ii) Q<0. 11.Write any two basic properties of electric charges. 12.Write any two limitations of Coulomb’s law. 13.Write properties of electric field lines. Why do two electric field lines not intersect with each other? 14.State Gauss’s theore...

Classes XI-XII Academic Session 2024-25 Composition of question paper for year-end examination/ Board Examination (Theory) Competency Focused Questions in the form of MCQs/ Case Based Questions, Source-based Integrated  Questions or any other type = 50%  Select response type questions (MCQ) = 20% Constructed response questions   (Short Answer Questions/Long  Answer type Questions, as per  existing pattern) = 30% Previous Year A cademic Session 2023-24   Composition of question paper for year-end examination/ Board Examination (Theory) Competency Focused Questions in the form of MCQs/ Case Based Questions, Source-based Integrated Questions or any other type = 40%  Select response type questions (MCQ) = 20% Constructed response questions  (Short Answer Questions/Long Answer type Questions, as per  existing pattern) = 40%

10. The frequency of AC input to a rectifier is 50 Hertz. What is the frequency of output wave form of (a) a half wave rectifier (b) a full wave rectifier? 9. Explain working of full wave rectifier. Draw input and output voltage waveforms. 8. Explain working of half wave diode rectifier. Draw input and output voltage waveforms. 7. What is the effect of  reverse bias on the deflection width? 6. What is the direction of drift current? 5. What is the effect of reverse bias on the potential barrier? 4. Give a circuit diagram to study the forward bias characteristic ? 3. Draw forward bas characteristic curve of pn junction diode. And define ac resistance ? Locate cut in voltage. 2. Which group's impurities are added to make p-type semiconductors? 1. Draw a band diagram of n type semiconductor ?

  Impulse: We sometimes encounter examples where a large force acts for a very short duration producing a finite change in momentum of the body. The product of this  force and time is called impulse. Impulse = Force × time duration = Change in momentum The force is called an impulsive force. Example 5.4   A batsman hits back a ball straight in the direction of the bowler without changing its initial speed of 12 m s –1 . If the mass of the ball is 0.15 kg, determine the impulse imparted to the ball. (Assume linear motion of the ball) Answer: Change in momentum = 0.15 × 12–(–0.15×12) = 3.6 N s, Impulse = 3.6 N s, in the direction from the batsman to the bowler. Equilibrium of a particle: Equilibrium of a particle is the situation when the net external force on the particle is zero. Equilibrium under three concurrent forces F1, F2 and F3 requires that the vector sum of the three forces is zero. F1 + F2 + F3 = 0 Example 5.6  A mass of 6 kg is suspended by a rope of lengt...

Unit VI: Optics  Chapter–9: Ray Optics and Optical Instruments  Ray Optics: Reflection of light, spherical mirrors, mirror formula, refraction of light, total internal reflection and optical fibers, refraction at spherical surfaces, lenses, thin lens formula, lens maker’s formula, magnification, power of a lens, combination of thin lenses in contact, refraction of light through a prism. Optical instruments: Microscopes and astronomical telescopes (reflecting and refracting) and their magnifying powers.  Chapter–10: Wave optics:  Wave front and Huygen’s principle, reflection and refraction of plane wave at a plane surface using wave fronts. Proof of laws of reflection and refraction using Huygen’s principle. Interference, Young's double slit experiment and expression for fringe width (No derivation final expression only), coherent sources and sustained interference of light, diffraction due to a single slit, width of central maxima (qualitative treatment only). ...