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Showing posts from May, 2021

Conventional sources of energy

  Good source of energy   A good source of energy would be :-- 1.   Which would do a large amount of work per unit volume or mass. 2.   Which would be easily accessible 3.   Which would be easy to store and transport 4.   Which would be economical   Conventional sources of energy The conventional sources of energy are also called as non-renewable source of energy that are being used since   a long time.   1.           Fossil   fuels :--                                Fossil fuels are the fuels that are formed by the natural processes such as anaerobic decompositions of buried dead organisms and containing organic molecules that release the energy in combustion. Fossil fuels are so important because they can be burnt to produce significant amount of energy. Due to such exploitation of coal as a source of energy ,the use of the fossil fuels was the central to the industrial revolution. Increasing industrialization has led to better quality of life in whole world

electric generator

  Electric Generator   An electric generator converts the mechanical energy into electrical energy. In an electric generator, mechanical energy is used to rotate the conductor in a magnetic field to produce electricity. It works on the basis of electromagnetic induction. An electric generator consists of the rotating rectangular coil ABCD which is placed between the poles of a permanent magnet. There are two rings R1 and R2. The both rings R1 and R2 are connected by the ends of the rectangular coil. the inner side of the rings are made insulated. Brushes B1 and B2 are the electrical contact which produce the electric current between the stationary wires. These brushes B1 and B2 are kept pressed separately on the rings R1 and R2 respectively. The both two rings R1 and R2 are internally attached to an axle. The axle may be mechanically rotated from outside to rotate the coil inside the magnetic field. The outer ends of the two brushes are connected to the galvanometer. The ga

Electric motor

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  Electric motor                                                         An electric motor is rotating machine or device that converts the electrical energy to mechanical energy.   An electric motor is consists of a rectangular coil ABCD of insulated copper wire. The coil is placed between the two poles of magnetic field. The rectangular coil of the arms AB and CD are kept in such a manner that both rms are perpendicular to the direction of the magnetic field. The ends of the coil are connected to the two halves P and Q of a split ring. The inner side of the halves are insulated and attached to the axle. The external conducting edges of P and Q touch the two conducting stationary brushes X and Y respectively.   Working :--   A source of battery is used to enter   the current in the coil through conducting brushes X and flows back to the battery through brush Y. Now , the current in the arms of the rectangular coil AB is flowing from A to B And the   current in the

Electromagnetic induction, fleming's right hand rule

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                         Electromagnetic induction   When a current carrying conductor is placed in a magnetic field in such a manner that the direction of the current is perpendicular to the magnetic field , a force is experienced. This force causes the conductor to move.     Now suppose that a conductor is moving inside the magnetic field or magnetic field is changing around a fixed conductor. This was first studied by English physicist Michael Faraday. And faraday made an important discovery that how a moving magnet can be used to generate electric currents.     To illustrate , how a moving magnet can be used to generate electric currents.   Let us take a coil of wire AB with a large number of turns. And the ends of the coil is connected to the galvanometer       And take a bar magnet. And move its north pole towards the end B of the coil. Then we observed that there is a deflection in the needles of the Galvanometer. This indicates that there is a pr

Magnetism in medicine , Electromagnet

                          Electromagnet A electromagnet consists of a core of soft iron wrapped with a coil of insulated copper wire When s current is flowing through a solenoid , a strong magnetic field is produced inside a solenoid which can be used to magnetise a piece   of magnetic material (like soft iron ) when placed inside the coil . the magnet so formed is called as electromagnet.     Magnetism in medicine:--   ·      An electric current is always produced a magnetic field. ·      Every weak ion current produces a magnetic field. Every weak ion current that travel along the nerve cells in our body produce a magnetic field. ·      When we touch something , our nerve cells carry an electric impulses to the muscles we need to use. ·      This impulse produce a temporary magnetic field. These magnetic field are very weak and are one-billionth of the earth’s magnetic field. ·      Hearth and brain are the two main organs of the human body to produce the magne

Magnetic field due to a current in a solenoid , Force on a current-carrying conductor in a magnetic field, Fleming’s left hand rule, electromagnet

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  Magnetic field due to a current in a solenoid   Solenoid:-- Solenoid is a coil of many circular turns of insulated copper wire which are wrapped closely in the shape of a cylinder is called a solenoid. Magnetic field lines of the magnetic field near current carrying solenoid.       A solenoid having current is used to magnetise the rod inside it       The magnetic field around the current carrying solenoid is similar to the magnetic field around the bar magnet. One end of the solenoid behaves as (or act as) magnetic north pole Other end of the solenoid behaves as (or act as)   the magnetic south pole. In the solenoid   , The magnetic field   lines are In the form of the parallel straight lines.   This shows that magnetic field is same at every points insides   the   solenoid. That is , the magnetic field is uniform inside the solenoid. A electromagnet consists of a core of soft iron wrapped with a coil of insulated copper wire When s current is