XII/Physics-Support Material/Bengaluru Region/2024-25
INDEX
S. No Content
1. ➢ CHAPTER- 1. ELECTRIC CHARGES AND FIELDS
2. ➢ CHAPTER- 2. ELECTROSTATIC POTENTIAL AND CAPACITANCE
3. ➢ CHAPTER- 3. CURRENT ELECTRICITY
4. ➢ CHAPTER- 4. MOVING CHARGES & MAGNETISM
5. ➢ CHAPTER- 5. MAGNETISM & MATTER
6. ➢ CHAPTER- 6. ELECTRO MAGNETIC INDUCTION
7. ➢ CHAPTER- 7. ALTERNATING CURRENTS & ELECTRICAL
MACHINES
8. ➢ CHAPTER- 8. ELECTRO MAGNETIC WAVES
9. ➢ CHAPTER- 9. RAY OPTICS & OPTICAL INSTRUMENTS
10. ➢ CHAPTER- 10. WAVE OPTICS
11. ➢ CHAPTER- 11. DUAL NATURE OF RADIATION & MATTER
12. ➢ CHAPTER- 12. ATOMS
13. ➢ CHAPTER- 13. NUCLEI
14. ➢ CHAPTER- 14. SEMICONDUCTOR ELECTRONICS & DEVICES
15. CBSE SAMPLE PAPER 2024-25
16. CBSE PRACTICE PAPER -01
17. CBSE PRACTICE PAPER -02
,XII/Physics-Support Material/Bengaluru Region/2024-25
1. ELECTRIC CHARGES AND FIELDS
SYLLABUS
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).
GIST/FORMULAS/IMPORTANT DEFINITIONS/DIAGRAMS
ELECTRIC CHARGE
It is a scalar. SI unit is C.
METHODS OF CHARGING
• By friction
• By Induction
• By conduction
BASIC PROPERTIES OF ELECTRIC CHARGE
• Additivity of charges
• Charge is conserved
• Quantisation of charge
q =ne
COULOMB’S LAW
F = kq1q2/r2
k = 1/4πϵ0, ϵ0 = 8.854 × 10–12 C2 N–1m–2
FORCE BETWEEN MULTIPLE CHARGES
,XII/Physics-Support Material/Bengaluru Region/2024-25
SUPERPOSITION PRINCIPLE
CONTINUOUS CHARGE DISTRIBUTION
Linear charge density , λ = q/l
Surface charge density , σ =q/A
Volume charge density, ρ= q/V
ELECTRIC FIELD
E = F /q0
SI unit = N/C, it is a vector .
ELECTRIC FIELD DUE TO A POINT CHARGE
The direction of E is on a radial line from q, pointing outward if q is positive and inward if q is
negative.
ELECTRIC FIELD LINES
A line of force is a curve drawn in a field such that the tangent at each point on the curve gives the
direction of the field at that point.
PROPERTIES
i) Field lines start from positive charges and end at negative charges. If there is a single charge,
they may start or end at infinity.
(ii) In a charge-free region, electric field lines can be taken to be continuous curves without any
breaks.
(iii) Two field lines can never cross each other.
(iv) Electrostatic field lines do not form any closed loops.This follows from the conservative nature
of electric field.
, XII/Physics-Support Material/Bengaluru Region/2024-25
FIELD LINES DUE TO SOME SIMPLE CHARGE CONFIGURATIONS
INDEX
S. No Content
1. ➢ CHAPTER- 1. ELECTRIC CHARGES AND FIELDS
2. ➢ CHAPTER- 2. ELECTROSTATIC POTENTIAL AND CAPACITANCE
3. ➢ CHAPTER- 3. CURRENT ELECTRICITY
4. ➢ CHAPTER- 4. MOVING CHARGES & MAGNETISM
5. ➢ CHAPTER- 5. MAGNETISM & MATTER
6. ➢ CHAPTER- 6. ELECTRO MAGNETIC INDUCTION
7. ➢ CHAPTER- 7. ALTERNATING CURRENTS & ELECTRICAL
MACHINES
8. ➢ CHAPTER- 8. ELECTRO MAGNETIC WAVES
9. ➢ CHAPTER- 9. RAY OPTICS & OPTICAL INSTRUMENTS
10. ➢ CHAPTER- 10. WAVE OPTICS
11. ➢ CHAPTER- 11. DUAL NATURE OF RADIATION & MATTER
12. ➢ CHAPTER- 12. ATOMS
13. ➢ CHAPTER- 13. NUCLEI
14. ➢ CHAPTER- 14. SEMICONDUCTOR ELECTRONICS & DEVICES
15. CBSE SAMPLE PAPER 2024-25
16. CBSE PRACTICE PAPER -01
17. CBSE PRACTICE PAPER -02
,XII/Physics-Support Material/Bengaluru Region/2024-25
1. ELECTRIC CHARGES AND FIELDS
SYLLABUS
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).
GIST/FORMULAS/IMPORTANT DEFINITIONS/DIAGRAMS
ELECTRIC CHARGE
It is a scalar. SI unit is C.
METHODS OF CHARGING
• By friction
• By Induction
• By conduction
BASIC PROPERTIES OF ELECTRIC CHARGE
• Additivity of charges
• Charge is conserved
• Quantisation of charge
q =ne
COULOMB’S LAW
F = kq1q2/r2
k = 1/4πϵ0, ϵ0 = 8.854 × 10–12 C2 N–1m–2
FORCE BETWEEN MULTIPLE CHARGES
,XII/Physics-Support Material/Bengaluru Region/2024-25
SUPERPOSITION PRINCIPLE
CONTINUOUS CHARGE DISTRIBUTION
Linear charge density , λ = q/l
Surface charge density , σ =q/A
Volume charge density, ρ= q/V
ELECTRIC FIELD
E = F /q0
SI unit = N/C, it is a vector .
ELECTRIC FIELD DUE TO A POINT CHARGE
The direction of E is on a radial line from q, pointing outward if q is positive and inward if q is
negative.
ELECTRIC FIELD LINES
A line of force is a curve drawn in a field such that the tangent at each point on the curve gives the
direction of the field at that point.
PROPERTIES
i) Field lines start from positive charges and end at negative charges. If there is a single charge,
they may start or end at infinity.
(ii) In a charge-free region, electric field lines can be taken to be continuous curves without any
breaks.
(iii) Two field lines can never cross each other.
(iv) Electrostatic field lines do not form any closed loops.This follows from the conservative nature
of electric field.
, XII/Physics-Support Material/Bengaluru Region/2024-25
FIELD LINES DUE TO SOME SIMPLE CHARGE CONFIGURATIONS
