DDDD
DD
DEPARTMENT
DEPARTMENT
DDDDDDPOPOPPOP OF SCHOOL
OF SCHOOL EDUCATION
EDUCATION
MADURAI DISTRICT
MADURAI DISTRICT
12
Special Guide
, DEPARTMENT OF SCHOOL EDUCATION,
MADURAI DISTRICT.
12 PHYSICS
SPECIAL GUIDE
CHAIRPERSON
Thiru R . Swaminathan,
Chief Educational Officer, Madurai.
COORDINATOR : SUPERVISOR :
Thiru V. Rajasekaran, Thiru P. Kumaresan,
Headmaster ,Govt. HSS,Paravai. Convenor HSS & Headmaster ,
Govt. HSS, P.Ammapatti.
Team Of Teachers
Thiru S. Ponnaiah , Thiru R. Sivakumar ,
Govt. HSS - Uranganpatti. Elango Corp. HSS - Madurai.
Thiru R. Saravanakumar, Thiru T. Senthilmurugan,
Govt . HSS - E. Malampatti. Govt (B). HSS - T.Vadipatti.
Tmt. P. Karpagam, Thiru S. Karthick,
Govt ( G ). HSS- Alanganallur. Setupati HSS , Madurai.
Tmt. J. Shalini Devi, Tmt. R. Jacquline Esther Rani,
Govt. HSS - Muduvarpatti. Govt.HSS - Sedapatti.
Tmt. E. Janet Pamila, Thiru P. Anbarasu,
Govt ( G ).HSS - Y.Othakadai. Govt ( G ).HSS - Sholavanthan.
, CONTENTS
UNIT TITLE PAGE NO.
1 ELECTROSTATICS 1
2 CURRENT ELECTRICITY 11
3 MAGNETISM AND MAGNETIC EFFECT OF CURRENT 21
4 ELECTROMAGNETIC INDUCTION AND ALTERNATING CURRENT 32
5 ELECTROMAGNETIC WAVES 41
6 RAY OPTICS 45
7 WAVE OPTICS 52
8 DUAL NATURE OF RADIATION AND MATTER 58
9 ATOMIC AND NUCLEAR PHYSICS 64
10 ELECTRONICS AND COMMUNICATION 72
11 RECENT DEVELOPMENTS IN PHYSICS 86
, 1 . ELECTROSTATICS
2 MARK - QUESTIONS AND ANSWERS :
1. Write down Coulomb‟s law in vector form and mention what each term represents.
𝑞1 𝑞2
Coulomb’s law in vector form 𝐹 = 𝑘 𝑟
𝑟2
Here, 𝐹 - the force between point charges
𝑞1, 𝑞2 - magnitude of point charges
r - distance between the two charges
𝑟 - the unit vector pointing along the line joining 𝑞1, 𝑎𝑛𝑑 𝑞2
State coulomb‟s law in electrostatics.
The electrostatic force is directly proportional to the product of the magnitude of the two point charges and is
𝑞1𝑞2
inversely proportional to the square of the distance between them. i.e 𝐹 𝛼
𝑟2
2. State Gauss law in electrostatics.
𝑄
The total electric flux through a closed surface 𝜙𝐸 = ∈ .
0
Here Q is the net charge enclosed by the surface .
3. What is an electric dipole? Give few examples.
Two equal and opposite charges separated by a small distance constitute an electric dipole.
Examples : Water (H2O), ammonia (NH3), HCl and CO.
4. What is the general definition of electric dipole moment?
The magnitude of the electric dipole moment is equal to the product of the magnitude of one of the
charges and the distance between them. (i.e) 𝑝 = q 2a.
Its unit is coulomb meter (C m).
5. Define “Electrostatic potential”. Give its unit.
The electrostatic potential at a point is equal to the work done by an external force to bring a unit
positive charge with constant velocity from infinity to that point in the region of the external electric
field.
Its unit is volt (V).
6. Define potential difference. Give its unit.
The electric potential difference is defined as the work done by an external force to bring unit
positive charge from one point to another point against the electric field.
Its unit is volt (V)
7. Define Electrostatic potential energy . Give its unit.
Electrostatic potential energy for system of charges is equal to the work done to arrange the
charges in the given configuration.
Its unit is joule ( J ).
1
DD
DEPARTMENT
DEPARTMENT
DDDDDDPOPOPPOP OF SCHOOL
OF SCHOOL EDUCATION
EDUCATION
MADURAI DISTRICT
MADURAI DISTRICT
12
Special Guide
, DEPARTMENT OF SCHOOL EDUCATION,
MADURAI DISTRICT.
12 PHYSICS
SPECIAL GUIDE
CHAIRPERSON
Thiru R . Swaminathan,
Chief Educational Officer, Madurai.
COORDINATOR : SUPERVISOR :
Thiru V. Rajasekaran, Thiru P. Kumaresan,
Headmaster ,Govt. HSS,Paravai. Convenor HSS & Headmaster ,
Govt. HSS, P.Ammapatti.
Team Of Teachers
Thiru S. Ponnaiah , Thiru R. Sivakumar ,
Govt. HSS - Uranganpatti. Elango Corp. HSS - Madurai.
Thiru R. Saravanakumar, Thiru T. Senthilmurugan,
Govt . HSS - E. Malampatti. Govt (B). HSS - T.Vadipatti.
Tmt. P. Karpagam, Thiru S. Karthick,
Govt ( G ). HSS- Alanganallur. Setupati HSS , Madurai.
Tmt. J. Shalini Devi, Tmt. R. Jacquline Esther Rani,
Govt. HSS - Muduvarpatti. Govt.HSS - Sedapatti.
Tmt. E. Janet Pamila, Thiru P. Anbarasu,
Govt ( G ).HSS - Y.Othakadai. Govt ( G ).HSS - Sholavanthan.
, CONTENTS
UNIT TITLE PAGE NO.
1 ELECTROSTATICS 1
2 CURRENT ELECTRICITY 11
3 MAGNETISM AND MAGNETIC EFFECT OF CURRENT 21
4 ELECTROMAGNETIC INDUCTION AND ALTERNATING CURRENT 32
5 ELECTROMAGNETIC WAVES 41
6 RAY OPTICS 45
7 WAVE OPTICS 52
8 DUAL NATURE OF RADIATION AND MATTER 58
9 ATOMIC AND NUCLEAR PHYSICS 64
10 ELECTRONICS AND COMMUNICATION 72
11 RECENT DEVELOPMENTS IN PHYSICS 86
, 1 . ELECTROSTATICS
2 MARK - QUESTIONS AND ANSWERS :
1. Write down Coulomb‟s law in vector form and mention what each term represents.
𝑞1 𝑞2
Coulomb’s law in vector form 𝐹 = 𝑘 𝑟
𝑟2
Here, 𝐹 - the force between point charges
𝑞1, 𝑞2 - magnitude of point charges
r - distance between the two charges
𝑟 - the unit vector pointing along the line joining 𝑞1, 𝑎𝑛𝑑 𝑞2
State coulomb‟s law in electrostatics.
The electrostatic force is directly proportional to the product of the magnitude of the two point charges and is
𝑞1𝑞2
inversely proportional to the square of the distance between them. i.e 𝐹 𝛼
𝑟2
2. State Gauss law in electrostatics.
𝑄
The total electric flux through a closed surface 𝜙𝐸 = ∈ .
0
Here Q is the net charge enclosed by the surface .
3. What is an electric dipole? Give few examples.
Two equal and opposite charges separated by a small distance constitute an electric dipole.
Examples : Water (H2O), ammonia (NH3), HCl and CO.
4. What is the general definition of electric dipole moment?
The magnitude of the electric dipole moment is equal to the product of the magnitude of one of the
charges and the distance between them. (i.e) 𝑝 = q 2a.
Its unit is coulomb meter (C m).
5. Define “Electrostatic potential”. Give its unit.
The electrostatic potential at a point is equal to the work done by an external force to bring a unit
positive charge with constant velocity from infinity to that point in the region of the external electric
field.
Its unit is volt (V).
6. Define potential difference. Give its unit.
The electric potential difference is defined as the work done by an external force to bring unit
positive charge from one point to another point against the electric field.
Its unit is volt (V)
7. Define Electrostatic potential energy . Give its unit.
Electrostatic potential energy for system of charges is equal to the work done to arrange the
charges in the given configuration.
Its unit is joule ( J ).
1
