These comprehensive RBSE Class 10 Science Notes Chapter 13 Magnetic Effects of Electric Current will give a brief overview of all the concepts.
RBSE Class 10 Science Chapter 13 Notes Magnetic Effects of Electric Current
→ Magnetic effect of electric current-According to the scientist Oersted a magnetic field is established around a current carrying conductor or an electric circuit. It is called magnetic effect of electric current.
→ A magnetic field is a space around the magnet, in which the magnetic force can be detected.
→ North Pole – The pole of magnet which point towards the north pole of earth is called north seeking pole or north pole of magnet.
→ South Pole – The pole of magnet which points towards the south pole of the earth is called south seeking pole or south pole of magnet.
→ Same poles repel each other and the opposite poles attracts each other.
→ A compass needle is a small bar magnet. The ends of the compass needle point towards north and south directions.
→ To represent a magnetic field, field lines are used.
→ The space surrounding a magnet, where a compass needle defects is called magnetic field.
→ Magnetic field is a quantity that has both direction and magnitude.
→ Magnetic field lines emerges from the north pole of the magnet and merge at the south pole. Inside the magnet these magnetic field lines directs from the south pole towards the north pole of magnet. Thus the magnetic field lines are closed curves.
→ In the magnetic field, no two field lines are found to cross each other.
→ Field lines are shown closer together where the magnetic field is greater.
→ A metallic wire carrying an electric current has associated with it a magnetic field. The field lines about the wire consist of a series of concentric circles whose direction is given by the right-hand rule.
→ An electromagnet consists of a core of soft iron wrapped around with a coil of insulated copper wire.
→ The magnetic field produced by a given current in the conductor decreases as the distance from it increases. It can be noticed that the concentric circles representing the magnetic field around a current-carrying straight wire become larger and larger as we move away from it.
→ A coil of many circular turns of insulated copper wire wrapped closely in the shape of a cylinder is called a solenoid. Magnetic field inside a solenoid is uniform. When current flows through a solenoid, it acts as a magnet. Hence current carrying solenoid is called electromagnet. An electromagnet is used in electric bell, telegraph, medical science, crane etc.
→ A current-carrying conductor when placed in a magnetic field experiences a force. If the direction of the field and that of the current are mutually perpendicular to each other, then the force acting on the conductor will be perpendicular to both and will be given by Fleming’s left-hand rule.
→ An electric motor is a device that converts electric energy into mechanical energy.
→ The phenomenon of electromagnetic induction is the production of induced current in a coil placed in a region where the magnetic field changes with time. The magnetic field may change due to a relative motion between the coil and a magnet placed near to the coil. If the coil is placed near to a current-carrying conductor, the magnetic field may change either due to a change in the current through the conductor or due to the relative motion between the coil and conductor. The direction of the induced current is given by the Fleming’s right-hand rule.
→ A device that reverse the direction of flow of current through a circuit is called a commutator.
→ A generator converts mechanical energy into electrical energy. It works on the basis of electromagnetic induction.
→ A generator is of two types –
(i) AC generator – It produces alternating current. The direction of AC changes with time periodically.
(ii) DC generator – It produces direct current. DC flows in the same direction
i.e. its direction does not changed periodicals with time.
→ In our houses we receive AC electric power of 220 V with a frequency of 50 Hz. One of the wires in this supply is with red insulation, called live wire. The other one is of black insulation, which is a neutral wire. The potential difference between the two is 220 V. The third is the earth wire that has green insulation and this is connected to a metallic body deep inside earth. It is used as a safety measure to ensure that any leakage of current to a metallic body does not give any severe shock to a user.
→ Fuse is the most important safety device, used for protecting the circuits due to short-circuiting or overloading of the circuits.