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## Physics

 The CBSE class XII th syllabus in Physics has been given out below:       ClassXII (PHYSICS ) one paper Time: 3 Hours Max 70 marks Unit No. Title Marks Unit I Electrostatics 08 Unit II Current Electricity 07 Unit III Magnetic effect of current & Magnetism 08 Unit IV Electromagnetic Induction and Alternating current 08 Unit V Electromagnetic Waves 03 Unit VI Optics 14 Unit VII Dual Nature of Matter 04 Unit VIII Atoms and Nuclei 06 Unit IX Electronic Devices 07 Unit X Communication Systems 05 Total 70

Unit I: Electrostatics

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 fleld. 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).

Electric potential, 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 polarisation, 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. Van de Graaff generator.

Unit II: 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-I characteristics (linear and  non-linear), electrical energy and power, electrical resistivity and conductivity. Carbon resistors,  colour 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.
Kirchhoff's 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

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,
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.

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

Electromagnetic induction; Faraday's laws, induced emf and current; Lenz's Law, Eddy currents.  Self and mutual induction.
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,
wattless current.

Unit V: Electromagnetic waves

Need for displacement current, Electromagnetic waves and their characteristics (qualitative ideas
only). Transverse nature of electromagnetic waves.

Electromagnetic spectrum (radio waves, microwaves, infrared, visible, ultraviolet, X-rays, gamma
rays) including elementary facts about their uses.

Unit VI: Optics

Reflection of light, spherical mirrors, mirror formula. Refraction of light, total internal reflection  and its applications, optical fibres, refraction at spherical surfaces, lenses, thin lens formula, lensmaker's  formula. Magnification, power of a lens, combination of thin lenses in contact combination  of a lens and a mirror. Refraction and dispersion of light through a prism.
Scattering of light - blue colour of sky and reddish apprearance of the sun at sunrise and sunset.

Optical instruments : Human eye, image formation and accommodation correction of eye  defects (myopia, hypermetropia) using lenses. Microscopes and astronomical telescopes
(reflecting and refracting) and their magnifying powers.

Wave optics :Wave front and Huygen's principle, relection 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, coherent sources  and sustained interference of light. Diffraction due to a single slit, width of central maximum.  Resolving power of microscopes and astronomical telescopes. Polarisation, plane polarised
light Brewster's law, uses of plane polarised light and Polaroids.

Unit VII: Dual Nature of Matter and Radiation

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

Matter waves-wave nature of particles, de Broglie relation. Davisson-Germer experiment

(experimental details should be omitted; only conclusion should be explained).

Unit VIII: Atoms & Nuclei

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

Composition and size of nucleus, atomic masses, isotopes, isobars; isotones. Radioactivityalpha,  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

Energy bands in solids (Qualitative ideas only) conductors, insulator and semiconductors;  semiconductor diode – I-V characteristics in forward and reverse bias, diode as a rectifier; I-V  characteristics of LED, photodiode, solar cell, and Zener diode; Zener diode as a voltage regulator.  Junction transistor, transistor action, characteristics of a transistor, transistor as an amplifier  (common emitter configuration) and oscillator. Logic gates (OR, AND, NOT, NAND and NOR).
Transistor as a switch.

Unit X: Communication Systems

Elements of a communication system (block diagram only); bandwidth of signals (speech, TV  and digital data); bandwidth of transmission medium. Propagation of electromagnetic waves in  the atmosphere, sky and space wave propagation. Need for modulation. Production and detection
of an amplitude-modulated wave.

Practicals

Every student will perform atleast 15 experiments (7 from section A and 8 from Section B) The  activities mentioned here should only be for the purpose of demonstration. One Project of three
marks is to be carried out by the students.

B. Evaluation Scheme for Practical Examination:

 Two experiments one from each section - - - -8+8 Marks Practical record (experiments & activities) - - - - -6 Marks Project -- - - -- - - -- - ---- - - -- - - 3 Marks Viva on experiments & project -- --- -- ---- 5 Marks

SECTION A

Experiments

(Any 7 experiments out of the following to be performed by the students)

1. To find resistance of a given wire using metre bridge and hence determine the specific
resistance of its material

2. To determine resistance per cm of a given wire by plotting a graph of potential difference
versus current.

3. To verify the laws of combination (series/parallel) of resistances using a metre bridge.

4. To compare the emf of two given primary cells using potentiometer.
5. To determine the internal resistance of given primary cell using potentiometer.
6. To determine resistance of a galvanometer by half-deflection method and to find its fig
of merit .

7. To convert the given galvanometer (of known resistance and figure of merit) into an ammeter

and voltmeter of desired range and to verify the same.

8. To find the frequency of the a.c. mains with a sonometer. Activities

1. To measure the resistance and impedance of an inductor with or without iron core.
2. To measure resistance, voltage (AC/DC), current (AC) and check continuity of a given  circuit using multimeter.
3. To assemble a household circuit comprising three bulbs, three (on/off) switches, a fuse  and a power source.
4. To assemble the components of a given electrical circuit.

5. To study the variation in potential drop with length of a wire for a steady current.
6. 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

(Any 8 experiments out of the following to be performed by the students)

1. To find the value of v for different values of u in case of a concave mirror and to find the  focal length.
2. To find the focal length of a convex mirror, using a convex lens.
3. To find the focal length of a convex lens by plotting graphs between u and v or between  1/u and 1/v.
4. To find the focal length of a concave lens, using a convex lens.
5. To determine angle of minimum deviation for a given prism by plotting a graph between  angle of incidence and angle of deviation.
6. To determine refractive index of a glass slab using a travelling microscope.
7. To find refractive index of a liquid by using (i) concave mirror, (ii) convex lens and plane  mirror.
8. To draw the I-V characteristic curve of a p-n junction in forward bias and reverse bias.
9. To draw the characteristic curve of a zener diode and to determine its reverse break  down voltage.
10. To study the characteristic of a common - emitter npn or pnp transistor and to find out the
values of current and voltage gains.

Activities (For the purpose of demonstration only)

1. To identify a diode, an LED, a transistor, and IC, a resistor and a capacitor from mixed  collection of such items.

2. Use of multimeter to (i) identify base of transistor (ii) distinguish between npn and pnp  type transistors (iii) see the unidirectional flow of current in case of a diode and an LED  (iv) check whether a given electronic component (e.g. diode, transistor or IC) is in working  order.
3. To study effect of intensity of light (by varying distance of the source) on an L.D.R.
4. To observe refraction and lateral deviation of a beam of light incident obliquely on a glass  slab.
5. To observe polarization of light using two Polaroids.
6. To observe diffraction of light due to a thin slit.
7. To study the nature and size of the image formed by (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).
8. To obtain a lens combination with the specified focal length by using two lenses from the
given set of lenses.

SUGGESTED INVESTIGATORY PROJECTS

1 To study various factors on which the internal resistance/emf of a cell depends.
2. To study the variations, in current flowing, in a circuit containing a LDR, because of a variation.
(a) in the power of the incandescent lamp, used to 'illuminate' the LDR. (Keeping all the lamps  at a fixed distance).
(b) in the distance of a incandescent lamp, (of fixed power), used to 'illuminate' the LDR.
3. To find the refractive indices of (a) water (b) oil (transparent) using a plane mirror, a equiconvex lens,     (made from a glass of known refractive index) and an adjustable object needle.
4. To design an appropriate logic gate combinatin for a given truth table.
5. 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.
6. 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.

7. To estimate the charge induced on each one of the two identical styro foam (or pith) balls suspended   in a vertical plane by making use of Coulomb's law.

8. To set up a common base transistor circuit and to study its input and output characteristic and to  calculate its current gain.
9. 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.
10. To construct a switch using a transistor and to draw the graph between the input and output  voltage and mark the cut-off, saturation and active regions.
11. To study the earth's magnatic field using a tangent galvanometer.

Unit I: Electrostatics
Electric Charges; Conservation of charge, Coulomb’s law-force between two point charges, force      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 fleld. 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).

Electric potential, 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 polarisation, 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. Van de Graaff generator.
Unit II: 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-I characteristics (linear and      non-linear), electrical energy and power, electrical resistivity and conductivity. Carbon resistors,      colour 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.

Kirchhoff’s 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
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,
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.
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. lectromagnets and factors affecting
their strengths. Permanent magnets.
Unit IV: Electromagnetic Induction and Alternating Currents

Electromagnetic induction; Faraday’s laws, induced emf and current; Lenz’s Law, Eddy currents.
Self and mutual induction.
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,
wattless current.

Unit V: Electromagnetic waves
Need for displacement current, Electromagnetic waves and their characteristics (qualitative ideas
only). Transverse nature of electromagnetic waves.
Electromagnetic spectrum (radio waves, microwaves, infrared, visible, ultraviolet, X-rays, gamma
rays) including elementary facts about their uses.
Unit VI: Optics
Reflection of light, spherical mirrors, mirror formula. Refraction of light, total internal reflection      and its applications, optical fibres, refraction at spherical surfaces, lenses, thin lens formula, lensmaker’s
formula. Magnification, power of a lens, combination of thin lenses in contact combination      of a lens and a mirror. Refraction and dispersion of light through a prism.
Scattering of light - blue colour of sky and reddish apprearance of the sun at sunrise and sunset.
Optical instruments : Human eye, image formation and accommodation correction of eye      defects (myopia, hypermetropia) using lenses. Microscopes and astronomical telescopes
(reflecting and refracting) and their magnifying powers.

Wave optics:Wave front and Huygen's principle, relection 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, coherent sources      and sustained interference of light. Diffraction due to a single slit, width of central maximum.      Resolving power of microscopes and astronomical telescopes. Polarisation, plane polarised
light Brewster's law, uses of plane polarised light and Polaroids. Unit VII: Dual Nature of Matter and Radiation
Dual nature of radiation. Photoelectric effect, Hertz and Lenard’s observations; Einstein’s
photoelectric equation-particle nature of light.
Matter waves-wave nature of particles, de Broglie relation. Davisson-Germer experiment
(experimental details should be omitted; only conclusion should be explained).

Unit VIII: Atoms & Nuclei
Alpha-particle scattering experiment; Rutherford’s model of atom; Bohr model, energy levels,    Composition and size of nucleus, atomic masses, isotopes, isobars; isotones. Radioactivityalpha,      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

Energy bands in solids (Qualitative ideas only) conductors, insulator and semiconductors;      semiconductor diode – I-V characteristics in forward and reverse bias, diode as a rectifier; I-V      characteristics of LED, photodiode, solar cell, and Zener diode; Zener diode as a voltage regulator.      Junction transistor, transistor action, characteristics of a transistor, transistor as an amplifier      (common emitter configuration) and oscillator. Logic gates (OR, AND, NOT, NAND and NOR).
Transistor as a switch.

Unit X: Communication Systems

Elements of a communication system (block diagram only); bandwidth of signals (speech, TV      and digital data); bandwidth of transmission medium. Propagation of electromagnetic waves in      the atmosphere, sky and space wave propagation. Need for modulation. Production and detection
of an amplitude-modulated wave.
Practicals

Every student will perform atleast 15 experiments (7 from section A and 8 from Section B) The      activities mentioned here should only be for the purpose of demonstration. One Project of three
marks is to be carried out by the students.

B. Evaluation Scheme for Practical Examination

 Two experiments one from each section       8+8 Marks Practical record (experiments & activities)   6 Marks Project                                                        3 Marks                  Viva on experiments & project                        5 Marks

SECTION A

Experiments
(Any 7 experiments out of the following to be performed by the students)
1. To find resistance of a given wire using metre bridge and hence determine the specific
resistance of its material
2. To determine resistance per cm of a given wire by plotting a graph of potential difference
versus current.
3. To verify the laws of combination (series/parallel) of resistances using a metre bridge.

4. To compare the emf of two given primary cells using potentiometer.

5. To determine the internal resistance of given primary cell using potentiometer.
6. To determine resistance of a galvanometer by half-deflection method and to find its figure
of merit .

7. To convert the given galvanometer (of known resistance and figure of merit) into an ammeter
and voltmeter of desired range and to verify the same.
8. To find the frequency of the a.c. mains with a sonometer.

Activities
1. To measure the resistance and impedance of an inductor with or without iron core.
2. To measure resistance, voltage (AC/DC), current (AC) and check continuity of a given      circuit using multimeter.
3. To assemble a household circuit comprising three bulbs, three (on/off) switches, a fuse      and a power source.
4. To assemble the components of a given electrical circuit.
5. To study the variation in potential drop with length of a wire for a steady current.
6. 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
(Any 8 experiments out of the following to be performed by the students)

1. To find the value of v for different values of u in case of a concave mirror and to find the      focal    length.
2. To find the focal length of a convex mirror, using a convex lens.
3. To find the focal length of a convex lens by plotting graphs between u and v or between      1/u and 1/v.
4. To find the focal length of a concave lens, using a convex lens.
5. To determine angle of minimum deviation for a given prism by plotting a graph between  angle of incidence and angle of deviation.

6. To determine refractive index of a glass slab using a travelling microscope.
7. To find refractive index of a liquid by using (i) concave mirror, (ii) convex lens and plane      mirror.

8. To draw the I-V characteristic curve of a p-n junction in forward bias and reverse bias.
9. To draw the characteristic curve of a zener diode and to determine its reverse break  down voltage.

10. To study the characteristic of a common - emitter npn or pnp transistor and to find out the
values of current and voltage gains.
Activities (For the purpose of demonstration only)
1. To identify a diode, an LED, a transistor, and IC, a resistor and a capacitor from mixed
collection of such items.
2. Use of multimeter to (i) identify base of transistor (ii) distinguish between npn and pnp      type transistors (iii) see the unidirectional flow of current in case of a diode and an LED      (iv) check whether a given electronic component (e.g. diode, transistor or IC) is in working  order.
3. To study effect of intensity of light (by varying distance of the source) on an L.D.R.
4. To observe refraction and lateral deviation of a beam of light incident obliquely on a glass      slab.

5. To observe polarization of light using two Polaroids.
6. To observe diffraction of light due to a thin slit.
7. To study the nature and size of the image formed by (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).
8. To obtain a lens combination with the specified focal length by using two lenses from the
given set of lenses.

SUGGESTED INVESTIGATORY PROJECTS

2. To study the variations, in current flowing, in a circuit containing a LDR, because of a variation.

(a) in the power of the incandescent lamp, used to 'illuminate' the LDR. (Keeping all the lamps at              a fixed distance).
(b) in the distance of a incandescent lamp, (of fixed power), used to 'illuminate' the LDR.
3. To find the refractive indices of (a) water (b) oil (transparent) using a plane mirror, a equiconve xlens             , (made from a glass of known refractive index) and an adjustable object needle.
4. To design an appropriate logic gate combinatin for a given truth table.
5. 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.
6. To investigate the dependence, of the angle of deviation, on the angle of incidence, using a hollow              filled, one by one, with different transparent fluids.
7. To estimate the charge induced on each one of the two identical styro foam (or pith) balls suspended
in a vertical plane by making use of Coulomb's law.
8. To set up a common base transistor circuit and to study its input and output characteristic and to         calculate its current gain.
9. 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.
10. To construct a switch using a transistor and to draw the graph between the input and output               voltage and mark the cut-off, saturation and active regions.
11. To study the earth's magnatic field using a tangent galvanometer.