ppt magnetic field X class Module 2.ppt
- 1. CHAPTER - 13 MAGNETIC EFFECTS OF ELECTRIC CURRENT (Module 2/3) (Topics covered : 1. Force on current carrying conductor in magnetic field 2. Fleming Left hand rule 3. Electric Motor 4.Electromagnetic induction 5. Ist & 2nd experiment of Faraday.)
- 2. Force on a conductor carrying current in a magnetic field :- A.M.Ampere suggested that if a current carrying conductor produces a magnetic field and exerts a force on a magnet, then a magnet should also exerts a force on a current carrying conductor. Eg :- If an aluminium rod is suspended horizontally by a wire between the poles of a horse shoe magnet and current is passed through the wire, then the aluminium rod is displaced. If the direction of current is reversed, the direction of displacement is also reversed. The force exerted is maximum if the conductor is perpendicular to the magnetic field.
- 3. Fleming’s Left Hand Rule :- The direction of force (motion) of a current carrying conductor in a magnetic field is given by Fleming’s Left Hand Rule. It states that ‘ If we hold the thumb, fore finger and middle finger of the left hand perpendicular to each other such that the fore finger points in the direction of magnetic field, the middle finger points in the direction of current, then the thumb shows the direction of force (motion) of the conductor’.
- 4. ELECTRIC MOTOR A MOTOR IS A DEVICE WHICH CONVERTS ELECTRICAL ENERGY INTO MECHANICAL ENERGY.
- 5. Diagrm of Simple Motor Simple Motor
- 6. PRINCIPLE OF MOTOR A MOTOR WORKS ON THE PRINCIPLE THAT WHEN A RECTANGULAR COIL IS PLACED IN A MAGNETIC FIELD AND CURRENT IS PASSED THROUGH IT, A FORCE ACTS ON THE COIL WHICH ROTATES IT CONTINUOUSLY.
- 8. Electromagnetic induction:- (Michael Faraday) The motion of a magnet with respect to a coil or a change in the magnetic field induce a potential difference in the coil and produces induced current. This is called electromagnetic induction. i) Motion of a magnet with respect to a coil produces induced current :- If a magnet is moved towards or away from a coil of wire connected to a galvanometer, the galvanometer needle shows a deflection. This shows that current is induced in the coil due to the motion of the magnet.
- 9. ii) Change in magnetic field produces induced current :- Take two coils of wires wound around a cylindrical paper roll. Connect one coil to a battery and the other coil to a galvanometer. If current is passed through the first coil, the galvanometer needle shows a deflection in the second coil. If the current is disconnected, the needle moves in the opposite direction. This shows that current is in duced due to change in magnetic field.