Sample Papers, Important Questions, Notes - Class 12 Physics

Class 12 Physics Term Wise Syllabus

Unit I: Electrostatics

Chapter - 1: Electric Charges and Fields

Electric Charges; Conservation of charge, Coulomb's law-force between two point charges, forces between multiple charges; superposition principle and continuous charge distribution.

Electric field, electric field due to a point charge, electric field lines, electric dipole, electric field due to a dipole, torque on a dipole in uniform electric field. Electric flux, statement of Gauss's theorem and its applications to find field due to infinitely long straight wire, uniformly charged infinite plane sheet and uniformly charged thin spherical shell (field inside and outside).

Chapter - 2: Electrostatic Potential and Capacitance

Electric potential difference, electric potential due to a point charge, a dipole and system of charges; equipotential surfaces, electrical potential energy of a system of two point charges and of electric dipole in an electrostatic field.

Conductors and insulators, free charges and bound charges inside a conductor. Dielectrics and electric polarization, capacitors and capacitance, combination of capacitors in series and in parallel, capacitance of a parallel plate capacitor with and without dielectric medium between the plates, energy stored in a capacitor.

Unit II: Current Electricity

Chapter - 3: Current Electricity

Electric current, flow of electric charges in a metallic conductor, drift velocity, mobility and their relation with electric current; Ohm's law, electrical resistance, V-l characteristics (linear and non-linear), electrical energy and power, electrical resistivity and conductivity, Carbon resistors, color code for carbon resistors; series and parallel combinations of resistors; temperature dependence of resistance.

Internal resistance of a cell, potential difference and emf of a cell, combination of cells in series and in parallel, Kerchiefs laws and simple applications. Wheatstone bridge, metre bridge.Potentiometer - principle and its applications to measure potential difference and for comparing EMF of two cells; measurement of internal resistance of a cell.

Unit III: Magnetic Effects of Current and Magnetism

Chapter - 4: Moving Charges and Magnetism

Concept of magnetic field, Oersted's experiment.

Biot - Savart law and its application to current carrying circular loop.

Ampere's law and its applications to infinitely long straight wire. Straight and toroidal solenoids (only qualitative treatment), force on a moving charge in uniform magnetic and electric fields. Cyclotron.

Force on a current-carrying conductor in a uniform magnetic field, force between two parallel current-carrying conductors-definition of ampere, torque experienced by a current loop in uniform magnetic field; moving coil galvanometer-its current sensitivity and conversion to ammeter and voltmeter.

Chapter - 5: Magnetism and Matter

Current loop as a magnetic dipole and its magnetic dipole moment, magnetic dipole moment of a revolving electron, magnetic field intensity due to a magnetic dipole (bar magnet) along its axis and perpendicular to its axis, torque on a magnetic dipole (bar magnet) in a uniform magnetic field; bar magnet as an equivalent solenoid, magnetic field lines; earth's magnetic field and magnetic elements.

Para-, dia- and Ferro - magnetic substances, with examples. Electromagnets and factors affecting their strengths, permanent magnets.

Unit IV: Electromagnetic Induction and Alternating Currents

Chapter - 6: Electromagnetic Induction

Electromagnetic induction; Faraday's laws, induced EMF and current; Lend's Law, Eddy currents. Self and mutual induction.

Chapter - 7: Alternating Current

Alternating currents, peak and RMS value of alternating current/voltage: reactance and impedance; LC oscillations (qualitative treatment only), LCR series circuit, resonance; power in AC circuits, power factor, watt less current. AC generator and transformer.

Unit V: Electromagnetic waves

Chapter - 8: Electromagnetic Waves

Basic idea of displacement current, Electromagnetic waves, their characteristics, their Transverse nature (qualitative ideas only).Electromagnetic spectrum (radio waves, microwaves, infrared, visible, ultraviolet, X-rays, gamma rays) including elementary facts about their uses.

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 its applications, optical fibers, refraction at spherical surfaces, lenses, thin lens formula, lensometer's formula, magnification, power of a lens, combination of thin lenses in contact, refraction of light through a prism.

Scattering of light - blue color of sky and reddish appearance of the sun at sunrise and sunset.

Optical instruments: Microscopes and astronomical telescopes (reflecting and refracting) and their magnifying powers.

Chapter - 10: Wave Optics

Wave optics: Wave front ana Hagen's principle, reflection and refraction of plane wave at a plane surface using wave fronts. Proof of laws of reflection and refraction using Hagen's principle. Interference, Young's double slit experiment and expression for fringe width, coherent sources and sustained interference of light, diffraction due to a single slit, width of central maximum, resolving power of microscope and astronomical telescope, polarization, plane polarized light, Burster's law, uses of plane polarized light and Pol aroids.

Unit VII: Dual Nature of Radiation and Matter

Chapter - 11: Dual Nature of Radiation and Matter

Dual nature of radiation, Photoelectric effect, Hertz and Leonard's observations; Einstein's photoelectric equation-particle nature of light.

Matter waves-wave nature of particles, debrided relation, Davison-Germier experiment (experimental details should be omitted; only conclusion should be explained).

Unit VIII: Atoms and Nuclei

Chapter - 12: Atoms

lpha-particle scattering experiment; Rutherford's model of atom; Bohr model, energy levels, hydrogen spectrum.

Chapter - 13: Nuclei

Composition and size of nucleus, Radioactivity, alpha, beta and gamma particles/rays and their properties; radioactive decay law.

Mass-energy relation, mass defect; binding energy per nucleon and its variation with mass number; nuclear fission, nuclear fusion.

Unit IX: Electronic Devices

Chapter - 14: Semiconductor Electronics: Materials, Devices and Simple Circuits

Energy bands in conductors, semiconductors and insulators (qualitative ideas only)

Semiconductor diode - l-V characteristics in forward and reverse bias, diode as a rectifier;

Special purpose p-n junction diodes: LED, photodiode, solar cell and Zener diode and their characteristics, zener diode as a voltage regulator.

PRACTICALS

The record to be submitted by the students at the time of their annual examination has to include:

• Record of at least 15 Experiments [with a minimum of 6 from each section], to be performed by the students.
• Record of at least 5 Activities [with a minimum of 2 each from section A and section B], to be demonstrated by the teachers.
• The Report of the project to be carried out by the students.

Evaluation Scheme

Time Allowed: Three hours Max. Marks: 30

Two experiments one from each section = 8+8 Marks

Practical record [experiments and activities] = 6 Marks

Investigatory Project = 3 Marks

Viva on experiments, activities and project = 5 Marks

SECTION-A

Experiments

• To determine resistance per cm of a given wire by plotting a graph for potential difference versus current.
• To find resistance of a given wire using metre bridge and hence determine the resistivity (specific resistance) of its material.
• To verify the laws of combination (series) of resistances using a metre
• To verify the laws of combination (parallel) of resistances using a metre bridge.
• To compare the EMF of two given primary cells using potentiometer.
• To determine the internal resistance of given primary cell using potentiometer.
• To determine resistance of a galvanometer by half-deflection method and to find its figure of merit.
• To convert the given galvanometer (of known resistance and figure of merit) into a voltmeter of desired range and to verify the same.
• To convert the given galvanometer (of known resistance and figure of merit) into an ammeter of desired range and to verify the same.
• To find the frequency of AC mains with a sonometer.

Activities (For the purpose of demonstration only)

• To measure the resistance and impedance of an inductor with or without iron core.
• To measure resistance, voltage (AC/DC), current (AC) and check continuity of a given circuit using multimeter.
• To assemble a household circuit comprising three bulbs, three (on/off) switches, a fuse and a power source.
• To assemble the components of a given electrical circuit.
• To study the variation in potential drop with length of a wire for a steady current.
• To draw the diagram of a given open circuit comprising at least a battery, resistor/rheostat, key, ammeter and voltmeter. Mark the components that are not connected in proper order and correct the circuit and also the circuit diagram.

SECTION-B

Experiments

• To find the value of v for different values of u in case of a concave mirror and to find the focal length.
• To find the focal length of a convex mirror, using a convex lens.
• To find the focal length of a convex lens by plotting graphs between u and vor between 1/u and 1/v.
• To find the focal length of a concave lens, using a convex lens.
• To determine angle of minimum deviation for a given prism by plotting a graph between angle of incidence and angle of deviation.
• To determine refractive index of a glass slab using a travelling microscope.
• To find refractive index of a liquid by using convex lens and plane mirror.
• To draw the l-V characteristic curve for a p-n junction in forward bias and reverse bias.
• To draw the characteristic curve of a zener diode and to determine its reverse breaks down voltage.
• To determine the wavelength of a laser beam by diffraction.

Activities (For the purpose of demonstration only)

• To identify a diode, an LED, a resistor and a capacitor from a mixed collection of such items.
• Use of multimeter to see the unidirectional flow of current in case of a diode and an LED and check whether a given electronic component (e.g., diode) is in working order.
• To study effect of intensity of light (by varying distance of the source) on an LDR.
• To observe refraction and lateral deviation of a beam of light incident obliquely on a glass slab.
• To observe polarization of light using two Periods.
• To observe diffraction of light due to a thin slit.
• To study the nature and size of the image formed by a (i) convex lens, (ii) concave mirror, on a screen by using a candle and a screen (for different distances of the candle from the lens/mirror).
• To obtain a lens combination with the specified focal length by using two lenses from the given set of lenses.

Suggested Investigatory Projects

• To study various factors on which the internal resistance/EMF of a cell depends.
• To study the variations in current flowing in a circuit containing an LDR because of a variation in
  1. The power of the incandescent lamp, used to 'illuminate' the LDR (keeping all the lamps at a fixed distance).
  2. The distance of a incandescent lamp (of fixed power) used to 'illuminate' the LDR
• To find the refractive indices of (a) water (b) oil (transparent) using a plane mirror, an equi convex lens (made from a glass of known refractive index) and an adjustable object needle.
• To design an appropriate logic gate combination for a given truth table.
• To investigate the relation between the ratio of (i) output and input voltage and (ii) number of turns in the secondary coil and primary coil of a self-designed transformer.
• To investigate the dependence of the angle of deviation on the angle of incidence using a hollow prism filled one by one, with different transparent fluids.
• To estimate the charge induced on each one of the two identical styrofoam (or pith) balls suspended in a vertical plane by making use of Coulomb's law.
• To study the factor on which the self-inductance of a coil depends by observing the effect of this coil, when put in series with a resistor/(bulb) in a circuit fed up by an A.C. source of adjustable frequency.
• To study the earth's magnetic field using a tangent galvanometer.

Practical Examination for Visually Impaired Students ofClasses XI and XII Evaluation Scheme

Time Allowed: Two hours Max. Marks: 30

Identification/Familiarity with the apparatus = 5 marks

Written test (based on given/prescribed practicals) = 10 marks

Practical Record5 marksViva = 10 marks

General Guidelines

• The practical examination will be of two hour duration.
• A separate list of ten experiments is included here.
• The written examination in practical for these students will be conducted at the time of practical\ examination of all other students.
• The written test will be of 30 minutes duration.
• The question paper given to the students should be legibly typed. It should contain a total of 15 practical skill based very short answer type questions. A student would be required to answer any 10 questions.
• A writer may be allowed to such students as per CBSE examination rules.
• All questions included in the question papers should be related to the listed practical. Every question should require about two minutes to be answered.
• These students are also required to maintain a practical file. A student is expected to record at least five of the listed experiments as per the specific instructions for each subject. These practical should be duly checked and signed by the internal examiner.
• The format of writing any experiment in the practical file should include aim, apparatus required, simple theory, procedure, related practical skills, precautions etc.
• Questions may be generated jointly by the external/internal examiners and used for assessment.
• The viva questions may include questions based on basic theory/principle/concept, apparatus/ materials/chemicals required, procedure, precautions, sources of error etc.

A.Items for Identification/ familiarity with the apparatus for assessment in practical (All experiments)

Meter scale, general shape of the voltmeter/ammeter, battery/power supply, connecting wires, standard resistances, connecting wires, voltmeter/ammeter, meter bridge, screw gauge, jockey Galvanometer, Resistance Box, standard Resistance, connecting wires, Potentiometer, jockey, Galvanometer, Lichened cell, Daniel cell [simple distinction between the two vis-a-vis their outer (glass and copper) containers], rheostat connecting wires, Galvanometer, resistance box, Plug-in and tapping keys, connecting wires battery/power supply, Diode, Resistor (Wire-wound or carbon ones with two wires connected to two ends), capacitors (one or two types), Inductors, Simple electric/electronic bell, battery/power supply, Plug-in and tapping keys. Convex lens, concave lens, convex mirror, concave mirror, Core/hollow wooden cylinder, insulated wire, ferromagnetic rod, Transformer core, insulated wire.

B. List of Practical

• To determine the resistance per cm of a given wire by plotting a graph between voltage and current.
• To verify the laws of combination (series/parallel combination) of resistances by Ohm's law.
• To find the resistance of a given wire using a meter bridge and hence determine the specific resistance (resistivity) of its material.
• To compare the e.m.f of two given primary cells using a potentiometer.
• To determine the resistance of a galvanometer by half deflection method.
• To identify a resistor, capacitor, inductor and diode from a mixed collection of such items.
• To understand the principle of (i) a NOT gate (ii) an OR gate (iii)an AND gate and to make their equivalent circuits using a bell and cells/battery and keys /switches
• To observe the difference between (i) a convex lens and a concave lens (ii) a convex mirror and a concave mirror and to estimate the likely difference between the power of two given convex /concave lenses.
• To design an inductor coil and to know the effect of (i) change in the number of turns (ii) Introduction of ferromagnetic material as its core material on the inductance of the coil.
• To design a (i) step up (ii) step down transformer on a given core and know the relation between its input and output voltages.

Note: The above practical may be carried out in an experiential manner rather than recording observations.

Board Examination - Theory

Physics Question Paper Design

Practical : 30

• Internal Choice. There is no overall choice in the paper. However, there will be a least 33% internal choice.
• The above template is only a sample. Suitable internal variations may be made for gener-ating similar templates keeping the overall weightage to different form of questions and typology of questions same.