SIMPLIFIED STUDY MATERIAL (2023- 2024)
CLASS:12th
Physics
Prepared by Checked by
Dr. Dinesh Kumar Hemraj Uppadhayaya
Lecturer in Physics Lecturer in Physics
Govt. Victoria Girls Senior Sec. School SOE, GSSS Kapurthala
Patiala
Under the Guidance of
Dr. Rupesh Dewan
Principal GSSSS Bahadurgarh Patiala
( D.M. Physics Patiala)
INDEX
Electrostatics 1-6
Current Electricity 7-9
Magnetic Effect of Current and Magnetism 10-13
EMI & AC 14-16
EM Waves 17-18
Optics 19-26
Dual nature of Radiation and Matter 27-29
Atoms & Nuclei 30-35
Semiconductors 36-40
Some Important 5 Marks Questions 41
, Unit 1 (Electrostatics)
One marks
Q1. If both charges and distance between them is doubled then new electrostatic force
(a) F (b)2F (c)0 (d)none
Q2. What is the angle between electric dipole moment and electric field strength due to dipole on
equatorial line
(a)00 (b)90o (c)180 0 (d)none
Q3. Capacitance depends upon
(a) nature of conductor b) size of conductor (c) thickness of conductor (d)none
Q4 A soap bubble is given a negative charge. Then its radius
(a)decreases (b)increase (c)unchanged (d)nothing can perdicted
Q5. The capacitance of parallel plate capacitor increase
decrease of its area (b) increase of its distance (c)increase of its area (d)none
Q6. Unit of electric dipole moment is
(a)Cm (b)C/m (c)Cm2 (d)none
Q7. Work done to move the charge on equipotential surface from one point to another point
(a)never zero (b)zero (c) always positive (d) none
Q8. The direction of electric dipole moment is
(a) negative to positive charge (b) positive to negative charge
(c) in any direction(d) none
Q9. The direction of electric field
(a) positive to negative charge (b) negative to positive charge
(c) any direction(d) none
Q10.Electric potential is
(a) scalar (b)vector (c) depends upon charge (d) none
Q11. The no. of electrons for 1 C of charge is
(A) 6.25x1018 (B) 6.25x1019
(C). 6.25x1021 (D) 6.25x1023
Q12. If 1019 electrons are removed from a neutral metal plate, then the electric charge on the plate will
be
(A). -1.6 C (B). +1.6 C
© . 10+19 C (D). 10-19 C
Q13. Coulomb’s law is given by : F = k q1 q2 rn; where n is equal to
−1 1
(A) -2 (B) 2 (C) (D)
2 2
Q14. When air is replaced by a medium of dielectric constant k, then the electrostatic force between
two point charges
(A) remains unchanged (B) decreases by k times
(c ). increases by k times (D) increases by 2 k times
Q15. The electric field required to keep a water drop of mass ‘m’ just to remain suspended, when
charged with one electron, is
mg em
(A)m g (B). e m g (C) (D).
e g
Q16. An electric dipole of dipole moment p is placed in uniform electric field of strength E. If is
the angle between p and E, then potential energy of the dipole becomes maximum, when is
(A) 00 (B) 450 (C) 900 (D) 1800
Q17. A charge q is placed at the centre of a cube. The magnitute of electric flux through one of its
face will be
1
Prepared by Dr. Dinesh Kumar Lecturer in Physics
Govt Victoria Girls Sen. Sec. School Patiala
, q q q 6q
(A) (B) (C) (D)
0 3 0 6 0 0
Q18. If an electron is brought towards another electron, then electric potential energy of system
(A). increases (B). decreases
(C ). becomes zero (D). remains the same
Q19. What is the angle between electric dipole moment and electric field strength due to dipole on
axial line
(A)00 (B)90o (C)180 0 (D)none
Q20. S.I. unit of permittivity of free space ( 0 ) is
(A). C/N-m (B). N-m2/C2
2 2
(C ). C /(N-m) (D). C2/N-m2
Q21. Units of linear charge density is
(A) C-m (B) C-m-1 (C) C-m-2 (D) C-m-3
Q22. Absolute permittivity of free space is
(A) 8.85 x 10-9 (B) ) 8.85 x 109 (C) 8.85 x 10-12 (D) ) 8.85 x 1012
F12
Q23. The Ratio of is
F21
(A) >1 (B) <1 (C) =1 (D)0
Q24. If medium is introduced between the two charges then Electrostatic forces
(A) increases (B) decreases (C) same (D) none
Q25. An object has an excess charge of – 1.92 x 10 C. How many electrons does it have.
-7
(A) 1200 (B) 12000 (C) 120 (D) 12
Q26.Which of the following is not an insulator.
(A) glass (B) rubber (C) ebonite (D)human body
Q27.When a plastic comb is passed through dry hair, the charge acquired by the comb is
(A) negative (B) positive (C) some times negative (D) none
Q28. The force between two point charges q1 and q2 kept at some distance in air are attractive when
(A) q1 q2=0 (B) q1 q2< 0 (C) q1 q2>0 (D) None
Q29. Consider three charged bodies P,Q,R . If P and Q repel each other and P attracts R, what is the
nature of forces between Q and R.
(A) Attractive (B) repulsive (C) Net force zero (D) None
Q30. In fig two protons ( symbol p) and one elecytron ( symbol e) on straight line AB. The direction
of net electrostatic force on the central proton
(A) Towards A (B) Towards B (C) Net force is zero (D) none
Q31. A body can be negatively charged by
(A) Giving excess of electrons to it. (B) removing some electrons from it.
© giving some protons to it. (D) removing some neutrons from it
Q32. The point charges Q and –2Q are placed at some distance apart. If the electric field at the
location of Q is E, then the electrical field at the location of –2 will be
(A) –E/2 (B) –3E/2
(C) –E (D) –2E
Q33. An electric dipole placed in a non-uniform electric field experiences :
(A) both, a torque and a net force.
(B) only a force but no torque.
(C) only a torque but no net force.
(D) no torque and no net force.
2
Prepared by Dr. Dinesh Kumar Lecturer in Physics
Govt Victoria Girls Sen. Sec. School Patiala
, Q34. Two infinitely long parallel conducting plates having surface charge densities + and –
respectively are separated by a small distance. the medium between the plates is
vacuum. If 0 is the dielectric permittivity of vacuum, then the electric field in the region
between the plates is .
(A) 0 V m–1 (B) /2 0 V m–1
(C) / 0 V m–1 (D) 2 / 0 V m–1
Q35. Two small spheres each carrying a charge q placed r metres apart repel each other with a
force F. If one of the spheres is taken around the other one in a circular path of radius
r, the work done will be
(A) F x r (B) F x 2 r (C) F/2 r (D) zero
Q36. N identical spherical drops charged to the same potential V and combined to from a big
drop. The potential of the new drop will be
(A) V (B) V/N
(C) V N (D) V N2/3
Q37. A capacitor having capactiance of 2 F has a charge of 1 C on its plates. If the charge
on the plates is changed to 2 C, the new capacitance of the capacitor is
(A) 4 F (B) 2 F
(C) 1 F (D) 0 F
Q38. Two capacitors with capacitances C1 and C2 are charted to potentials V1 and V2
respectively. when they are connected in parallel, the ratio of their respective charges
is(karnataka2000)
(A) C1/C2 (B) V1/V2
(C) V12/V22 (D) C12/C22
Q39. A dielectric is placed in between the two parallel plates of a capacitor . The dielectric
constant of the dielectric is K. If the initial capacitance is C, then modified capacitance
will be
(A) KC
(B) (K+1) C
(C) (K+1) C/2
(D) (K–1) C
Q40. A given charge situated at a certain distance from an electric dipole of very small length
along its axial line experiences a force F. If the distance of the charge is doubled, the
force on charge will become :
(A) 2 F (B) F/2
(C) F/4 (D) F/8
Q41. Static electricity is produced due to
3
Prepared by Dr. Dinesh Kumar Lecturer in Physics
Govt Victoria Girls Sen. Sec. School Patiala
CLASS:12th
Physics
Prepared by Checked by
Dr. Dinesh Kumar Hemraj Uppadhayaya
Lecturer in Physics Lecturer in Physics
Govt. Victoria Girls Senior Sec. School SOE, GSSS Kapurthala
Patiala
Under the Guidance of
Dr. Rupesh Dewan
Principal GSSSS Bahadurgarh Patiala
( D.M. Physics Patiala)
INDEX
Electrostatics 1-6
Current Electricity 7-9
Magnetic Effect of Current and Magnetism 10-13
EMI & AC 14-16
EM Waves 17-18
Optics 19-26
Dual nature of Radiation and Matter 27-29
Atoms & Nuclei 30-35
Semiconductors 36-40
Some Important 5 Marks Questions 41
, Unit 1 (Electrostatics)
One marks
Q1. If both charges and distance between them is doubled then new electrostatic force
(a) F (b)2F (c)0 (d)none
Q2. What is the angle between electric dipole moment and electric field strength due to dipole on
equatorial line
(a)00 (b)90o (c)180 0 (d)none
Q3. Capacitance depends upon
(a) nature of conductor b) size of conductor (c) thickness of conductor (d)none
Q4 A soap bubble is given a negative charge. Then its radius
(a)decreases (b)increase (c)unchanged (d)nothing can perdicted
Q5. The capacitance of parallel plate capacitor increase
decrease of its area (b) increase of its distance (c)increase of its area (d)none
Q6. Unit of electric dipole moment is
(a)Cm (b)C/m (c)Cm2 (d)none
Q7. Work done to move the charge on equipotential surface from one point to another point
(a)never zero (b)zero (c) always positive (d) none
Q8. The direction of electric dipole moment is
(a) negative to positive charge (b) positive to negative charge
(c) in any direction(d) none
Q9. The direction of electric field
(a) positive to negative charge (b) negative to positive charge
(c) any direction(d) none
Q10.Electric potential is
(a) scalar (b)vector (c) depends upon charge (d) none
Q11. The no. of electrons for 1 C of charge is
(A) 6.25x1018 (B) 6.25x1019
(C). 6.25x1021 (D) 6.25x1023
Q12. If 1019 electrons are removed from a neutral metal plate, then the electric charge on the plate will
be
(A). -1.6 C (B). +1.6 C
© . 10+19 C (D). 10-19 C
Q13. Coulomb’s law is given by : F = k q1 q2 rn; where n is equal to
−1 1
(A) -2 (B) 2 (C) (D)
2 2
Q14. When air is replaced by a medium of dielectric constant k, then the electrostatic force between
two point charges
(A) remains unchanged (B) decreases by k times
(c ). increases by k times (D) increases by 2 k times
Q15. The electric field required to keep a water drop of mass ‘m’ just to remain suspended, when
charged with one electron, is
mg em
(A)m g (B). e m g (C) (D).
e g
Q16. An electric dipole of dipole moment p is placed in uniform electric field of strength E. If is
the angle between p and E, then potential energy of the dipole becomes maximum, when is
(A) 00 (B) 450 (C) 900 (D) 1800
Q17. A charge q is placed at the centre of a cube. The magnitute of electric flux through one of its
face will be
1
Prepared by Dr. Dinesh Kumar Lecturer in Physics
Govt Victoria Girls Sen. Sec. School Patiala
, q q q 6q
(A) (B) (C) (D)
0 3 0 6 0 0
Q18. If an electron is brought towards another electron, then electric potential energy of system
(A). increases (B). decreases
(C ). becomes zero (D). remains the same
Q19. What is the angle between electric dipole moment and electric field strength due to dipole on
axial line
(A)00 (B)90o (C)180 0 (D)none
Q20. S.I. unit of permittivity of free space ( 0 ) is
(A). C/N-m (B). N-m2/C2
2 2
(C ). C /(N-m) (D). C2/N-m2
Q21. Units of linear charge density is
(A) C-m (B) C-m-1 (C) C-m-2 (D) C-m-3
Q22. Absolute permittivity of free space is
(A) 8.85 x 10-9 (B) ) 8.85 x 109 (C) 8.85 x 10-12 (D) ) 8.85 x 1012
F12
Q23. The Ratio of is
F21
(A) >1 (B) <1 (C) =1 (D)0
Q24. If medium is introduced between the two charges then Electrostatic forces
(A) increases (B) decreases (C) same (D) none
Q25. An object has an excess charge of – 1.92 x 10 C. How many electrons does it have.
-7
(A) 1200 (B) 12000 (C) 120 (D) 12
Q26.Which of the following is not an insulator.
(A) glass (B) rubber (C) ebonite (D)human body
Q27.When a plastic comb is passed through dry hair, the charge acquired by the comb is
(A) negative (B) positive (C) some times negative (D) none
Q28. The force between two point charges q1 and q2 kept at some distance in air are attractive when
(A) q1 q2=0 (B) q1 q2< 0 (C) q1 q2>0 (D) None
Q29. Consider three charged bodies P,Q,R . If P and Q repel each other and P attracts R, what is the
nature of forces between Q and R.
(A) Attractive (B) repulsive (C) Net force zero (D) None
Q30. In fig two protons ( symbol p) and one elecytron ( symbol e) on straight line AB. The direction
of net electrostatic force on the central proton
(A) Towards A (B) Towards B (C) Net force is zero (D) none
Q31. A body can be negatively charged by
(A) Giving excess of electrons to it. (B) removing some electrons from it.
© giving some protons to it. (D) removing some neutrons from it
Q32. The point charges Q and –2Q are placed at some distance apart. If the electric field at the
location of Q is E, then the electrical field at the location of –2 will be
(A) –E/2 (B) –3E/2
(C) –E (D) –2E
Q33. An electric dipole placed in a non-uniform electric field experiences :
(A) both, a torque and a net force.
(B) only a force but no torque.
(C) only a torque but no net force.
(D) no torque and no net force.
2
Prepared by Dr. Dinesh Kumar Lecturer in Physics
Govt Victoria Girls Sen. Sec. School Patiala
, Q34. Two infinitely long parallel conducting plates having surface charge densities + and –
respectively are separated by a small distance. the medium between the plates is
vacuum. If 0 is the dielectric permittivity of vacuum, then the electric field in the region
between the plates is .
(A) 0 V m–1 (B) /2 0 V m–1
(C) / 0 V m–1 (D) 2 / 0 V m–1
Q35. Two small spheres each carrying a charge q placed r metres apart repel each other with a
force F. If one of the spheres is taken around the other one in a circular path of radius
r, the work done will be
(A) F x r (B) F x 2 r (C) F/2 r (D) zero
Q36. N identical spherical drops charged to the same potential V and combined to from a big
drop. The potential of the new drop will be
(A) V (B) V/N
(C) V N (D) V N2/3
Q37. A capacitor having capactiance of 2 F has a charge of 1 C on its plates. If the charge
on the plates is changed to 2 C, the new capacitance of the capacitor is
(A) 4 F (B) 2 F
(C) 1 F (D) 0 F
Q38. Two capacitors with capacitances C1 and C2 are charted to potentials V1 and V2
respectively. when they are connected in parallel, the ratio of their respective charges
is(karnataka2000)
(A) C1/C2 (B) V1/V2
(C) V12/V22 (D) C12/C22
Q39. A dielectric is placed in between the two parallel plates of a capacitor . The dielectric
constant of the dielectric is K. If the initial capacitance is C, then modified capacitance
will be
(A) KC
(B) (K+1) C
(C) (K+1) C/2
(D) (K–1) C
Q40. A given charge situated at a certain distance from an electric dipole of very small length
along its axial line experiences a force F. If the distance of the charge is doubled, the
force on charge will become :
(A) 2 F (B) F/2
(C) F/4 (D) F/8
Q41. Static electricity is produced due to
3
Prepared by Dr. Dinesh Kumar Lecturer in Physics
Govt Victoria Girls Sen. Sec. School Patiala
