The PPT includes the concepts in a very simple and precise manner. The videos are been included using Modernised Lab Instruments to make the concepts quite interesting and easy to understand....

1. Magnetic Effects of Current
Class 10
Prepared by: Vivek Sawhney, KV JALGAON
Prepared by: Vivek Sawhney, KV NMU Jalgaon

2. OERSTED EXPERIMENT
• In 1820, Hans Christian Oersted performed an important experiment which showed that there was a
connection between electricity and magnetism.
• When a current was switched on through a wire, it made a compass needle turn so that it was at right
angles to the wire. The current had produced a magnetic field strong enough to cause the compass needle
to turn.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

3. OERSTED EXPERIMENT
Prepared by: Vivek Sawhney, KV NMU Jalgaon

4. Observations
• 1. When electric current is passed through the wire from South (S) to North (N) directions and the wire is placed
over (O) the compass needle, the compass needle gets deflected towards West (W) direction (SNOW Rule).
• 2. On reversing the direction of current in the wire, the compass needle gets deflected in the opposite direction.
• 3. When current is switched off, then there is no deflection in the compass needle.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

5. CONCLUSION
• The deflection of compass needle, whenever there is current in the wire shows that a
current carrying wire produces a magnetic field around it.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

6. What is a Magnetic Field?
• Magnetic Field is the region around a magnetic material or a moving electric charge within which the force
of magnetism acts.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

7. MAGNETIC FIELD LINES
• Magnetic field lines are a visual tool used to represent magnetic fields. They describe the direction of the magnetic
force on a north monopole at any given position
• The density of the lines indicates the magnitude of the field. Taking an instance, the magnetic field is stronger and
crowded near the poles of a magnet. As we move away from the poles it is weak and the lines become less dense.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

8. MAGNETIC FIELD LINES
Prepared by: Vivek Sawhney, KV NMU Jalgaon

9. MAGNETIC FIELD LINES
Prepared by: Vivek Sawhney, KV NMU Jalgaon

10. Fun with Magnets
• Click here to Watch
Prepared by: Vivek Sawhney, KV NMU Jalgaon

11. PROPERTIES OF MAGNETIC FIELD
LINES
• Magnetic field lines never cross each
• other
• The density of the field lines indicates the strength of the field
• Magnetic field lines always make closed-loops
• Magnetic field lines always emerge or start from the north pole and terminate at the south pole.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

12. Magnetic field due to straight current
carrying wire
Prepared by: Vivek Sawhney, KV NMU Jalgaon

13. Magnetic field due to straight current
carrying wire
• The Magnetic field lines around a straight conductor carrying current are concentric circles whose centres
lie on the wire.
• The direction of magnetic field lines can be determined using Right-Hand Thumb Rule.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

14. Right Hand Thumb Rule
• Rule. ... If a current carrying conductor is imagined to be held in right hand such that thumb points in
direction of current, then curled fingers of hand indicate the direction of magnetic field.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

15. Right Hand Thumb Rule
Prepared by: Vivek Sawhney, KV NMU Jalgaon

16. The factors affecting the magnetic
field due to a Straight Wire
• Strength of the magnetic field is directly proportional to the magnitude of current flowing in the conductor.
Greater the current in the conductor, stronger will be the magnetic field will be produced.
• Strength of the magnetic field is inversely proportional to the distance from the wire.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

17. Magnetic field due to a circular loop of
wire
• The magnetic field around a straight current carrying conductor or wire can be increased by bending the
wire into circular loop. ...
• Each small section of current carrying wire contributes to magnetic field lines.
• At the centre of circular wire, field lines become straight and perpendicular to the plane of coil.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

18. Prepared by: Vivek Sawhney, KV NMU Jalgaon

19. Prepared by: Vivek Sawhney, KV NMU Jalgaon

20. Clock-Face Rule
Prepared by: Vivek Sawhney, KV NMU Jalgaon

21. Factors affecting the strength of
magnetic field
• The magnitude of magnetic field is directly proportional to the magnitude of current through the loop.
i.e. B∝I.
• The magnitude of magnetic field is inversely proportional to the radius of the circular loop. i.e. B∝1/r
• B∝ n ( no of turns)
Prepared by: Vivek Sawhney, KV NMU Jalgaon

22. Magnetic Field due to a Solenoid
• A coil with many circular close turns of insulated copper wire (like a cylinder as shown above) is
a solenoid.
• One end of such a solenoid behaves like the north pole and the other as a south pole. Therefore magnetic
field due to current in the solenoid is similar to a bar magnet.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

23. Magnetic Field due to a Solenoid
Prepared by: Vivek Sawhney, KV NMU Jalgaon

24. Factors by which strength of Magnetic
Field due to a Solenoid can be increased
• Number of turns in the solenoid : The larger number of turns in the solenoid, stronger is the magnetic field
produced.
• Strength of current : The larger the current passed through the solenoid, stronger is the magnetic field produced.
• Nature of the core material : By winding the coil over a soft iron cylinder, called core, the magnetic field can be
increased several thousands times.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

25. Magnetising a Coil
• Click here to Watch
Prepared by: Vivek Sawhney, KV NMU Jalgaon

26. Electromagnet
Prepared by: Vivek Sawhney, KV NMU Jalgaon

27. Factors by which strength of Magnetic
Field of an Electromagnet can be
increased
• nature of the core material,
• strength of the current passing through the core,
• the number of turns of wire on the core and the shape and size of the core.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

28. Applications of Electromagnets
• Motors and generators.
• Transformers
• Electric bells and buzzers.
• Loudspeakers and headphones.
• Magnetic recording and data storage equipment: tape recorders,
VCRs, hard disks.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

29. An Experiment to Demonstrate the
force acting on a current carrying
conductor placed in a magnetic field:
Prepared by: Vivek Sawhney, KV NMU Jalgaon

30. Observations
• 1. On closing the key, the conductor gets displaced towards right.
• 2. On reversing the direction of current, the conductor gets displaced towards left.
• 3. On changing the polarity of horse shoe magnet, the direction of force acting on the current carrying conductor gets reversed.
• 4. When current carrying conductor is placed perpendicular to the direction of magnetic field, the maximum displacement occurs
indicating the maximum force on the conductor.
• 5. On placing the conductor || to the direction of magnetic field no displacement is noticed.
•
Prepared by: Vivek Sawhney, KV NMU Jalgaon

31. Conclusion
• The displacement of conductor shows that force it
experiences some when it carries some current and placed in
a magnetic field.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

32. Fleming Left Hand Rule
Prepared by: Vivek Sawhney, KV NMU Jalgaon

33. Electric Motor
• An electric motor is a machine which converts electrical energy into mechanical energy. ...
Prepared by: Vivek Sawhney, KV NMU Jalgaon

34. Electric Motor
Prepared by: Vivek Sawhney, KV NMU Jalgaon

35. Electric Motor- Components
• Power Source: A simple motor usually has a DC power source. It supplies power to the motor armature or field coils.
• Commutator: It is the rotating interface of the armature coil with a stationary circuit.
• Field Magnet: The magnetic field helps to produce a torque on the rotating armature coil by the virtue of Fleming’s left-hand rule.
• Armature Core: Holds the armature coil in place and provides mechanical support.
• Armature Coil: It helps the motor to run.
• Brushes: It is a device that conducts current between stationary wires and moving parts, most commonly the rotating shaft.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

36. Working
Prepared by: Vivek Sawhney, KV NMU Jalgaon

37. • When the current begins to flow, current flows through brush X, then A to B, B
to C, C to D and then to brush Y and into the battery.
• Now applying Fleming's Left Hand Rule to wire AB, Current is along AB,
Magnetic Field is as shown (North-> South), the motion of the wire
is downwards.
• Now applying Fleming's Left Hand Rule to wire CD, Current is along CD,
Magnetic Field is as shown (North-> South), the motion of the wire is upwards.
• The rectangular coil begins to move in the anti-clockwise direction
• Note that during anti-clockwise motion, the split rings and axle also move,
whereas the brushes don't move.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

38. • After half a rotation, Wire CD and Split ring Q moves to the left. Wire AB and
Split ring P moves to right. Brushes X and Y donot move.
• Now applying Fleming's Left Hand Rule to wire CD, Current is along DC. (Battery -
> Split ring Q -> DC , Magnetic Field is as shown (North-> South), the motion of the
wire is downwards.
• Now applying Fleming's Left Hand Rule to wire AB, Current is along BA. (Battery ->
Split ring Q -> DC --> CB -> BA --> Split ring P) , Magnetic Field is as shown (North->
South), the motion of the wire is upwards.
• So, again the coil rotates in the anti-clockwise direction.
• The reversal of current in the coil results in the continous rotation of the coil. The
reversal of current is achieved by the commutator rings
Prepared by: Vivek Sawhney, KV NMU Jalgaon

39. Applications of Motors
• vacuum cleaners
• dishwashers
• computer printers
• fax machines
• video cassette recorders
• sewage treatment plants and water pumping stations
Prepared by: Vivek Sawhney, KV NMU Jalgaon

40. Electromagnetic Induction
• The flow of induced current in a coil when a magnetic field changes in the region of the coil, this
phenomenon is called Electromagnetic Induction.
• Whenever there is a change in the magnetic field in the region of the coil, current flows.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

41. Prepared by: Vivek Sawhney, KV NMU Jalgaon

42. Prepared by: Vivek Sawhney, KV NMU Jalgaon

43. Faraday’s Laws
• Whenever a conductor is placed in a varying magnetic field, an electromotive force is induced. If the
conductor circuit is closed, a current is induced which is called induced current.
• The induced emf in a coil is equal to the rate of change of flux linkage.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

44. Fleming Right Hand Rule
Prepared by: Vivek Sawhney, KV NMU Jalgaon

45. Electric Generator
• A generator is a machine that converts available mechanical energy into
electrical energy. It works on the principle of Faraday’s Law of Electromagnetic
Induction.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

46. Prepared by: Vivek Sawhney, KV NMU Jalgaon

47. Prepared by: Vivek Sawhney, KV NMU Jalgaon

48. Domestic Electric Circuits
Prepared by: Vivek Sawhney, KV NMU Jalgaon

49. Domestic Electric Circuits
• Colour code of these wires is
• 1. Live wire - Red
• 2. Neutral wire - Black
• 3. Earth Wire – Green
Prepared by: Vivek Sawhney, KV NMU Jalgaon

50. • Two separate circuits are used in domestic circuits.
• 1. A circuit of 5 A current rating used for devices such as bulbs, tubelight, fan, TV, computer, etc.
• 2. A circuit of 15 A current rating used for devices such as air conditioners, geysers, microwave oven, etc.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

51. Earthing
• The process of connecting the metallic body of electrical appliances such as refrigerator, microwave oven, electric press, toaster, air
conditioners etc, to the earth wire which offers a low resistance conducting path for the current is called earthing. The earth wire is
connected to metal plate like copper plate buried deep in the earth near our houses.
• Role of Earth wire:
• Earth wire is used as a safety measure. Accidentally, if there is any leakage of current in an electrical appliances having metallic bodies,
it is transferred to the earth through the earth wire and protects the user to get an electric shock.
Prepared by: Vivek Sawhney, KV NMU Jalgaon

52. Short- Circuiting
Prepared by: Vivek Sawhney, KV NMU Jalgaon

53. Overloading
Prepared by: Vivek Sawhney, KV NMU Jalgaon

54. For more videos: Subscribe my channel
• https://www.youtube.com/c/VIVEKSAWHNEY-FunwithPhysics
Prepared by: Vivek Sawhney, KV NMU Jalgaon

55. Prepared by: Vivek Sawhney, KV NMU Jalgaon