The Science

Eddy currents:-        The current induced in a conductor (metal sheet or metal block)  in form of clesed loops .these loops are called eddy currents because these currents look like Eddies or which pods. These current are also known as focarlt current.  Experiments :-   https://instagram.com/sachin_dreamboy?igshid=1647004f4d5r6 Explanation :- When the circuit is suritered  in, the current shorts growing through the solenoid. As the current grows, the magnetic field lines along the axis of the solenoid and hence the magnetic flux through the dix also increases from zero yo some finite value. Due to this, induced current are produced in the disc and the disc is converted into a small magnet. If the upper face of the soft iron core acquires N polarity in accordance with lenz's lawer face of the disc acquires N polarity due to repulsion face between the upper face of the soft iron core and the lower face of the disc ,the disc is throw...

History of Lenz's Law:- Faraday could only tell ,when and how much induced emf is produced. It was the Russian scientist H. F. E lenz who gave us in 1833 the direction of the induced emf. His experiments are known as lenz law.  Explanation :- Connect a galvanometer to coil. Take a magnet NS and move into the coil with it's north pole downlwords. The deflection in the galvanometer is towards left which indicates that the current in the coil flows in anticlockwise direction as seen from above. Hence upper force of the coil has acquired north polarity due to flow of induced current through it.  If we move the magnet out of the coil ,the deflection us towards right, indicates that the current is upper face of the coil flows in clockwise direction as seen from above, hence upper face of the coil has aquired north polarity due to flow if induced current through it.  Similarly, if the magnet is moved into or out of the coil with its aouth pole downward ...

The results of Faraday's Experiments on electromagnetic interaction are known as faraday's law  of electromagnetic induction.  1.Faraday's First law of electromagnetic induction :- Whenever magnetic flux linked with a circuit changes, induced EMF is produced. The induced emf losts as long as change in magnetic flux continue.  2. Faraday's second Law of electomagnetic Induction :- The magnitude of the emf is directly proportional to the rate of change of the magnetic flux linked with circuit.                MATHEMATICALLY                 ε  ∝ dΦ/dt                                 ε= - kdΦ/dt  Here - k is constant of proportionality .In SI k=1 ,-ve sign indicates that the induced emf gas got opposing nature ie direction of flow of current due to induced emf is such that i...

•Electromagnetic induction :- The phenomenon of production of electric current in a coil, when the magnetic flux linked with the coil is changed is called electromagnetic induction.  •Magnetic flux :- Magnetic flux is a measure of number magnetic field lines passing through same surfaces.  It is a scalar quantity. It is denoted by  Φ. •Unit of magnetic flux :- SI unit of magnetic flux is weber (wb).    For normal field to surface                Φ=BS When B=1T            S=1m² Then               Φ=1T m²              =1weber.  •Weber:- The magnetic flux with a surface are of 1 m² held normally in a magnetic field of 1T is called one weber.      Cgs unit of Φ is maxwell(Mx).                Φ=BS If B=1 gauss ...

1.Diamagnetic substances :- The substances which are feebly magnetised in a direction opposite to that of the magnetising field when placed in it are called diamagnetic substances.  Examples:- Bismith, Antimony, copper, gold, murcury, water, alcohol, air, hydrogen, etc are called diamagnetic substances.  2.Paramagnetic substances :- The substances which are feebly magnetised in direction of the magnetising field when placed in it are called paramagnetic substances.  Example :- Aluminum, platinum, chromium, manganese, copper sulphate, Crown glass etc are some of paramagnetic substances 3. Ferromagnetic substances :- The substance which are strongly magnetised in the direction of magnetising field in which they are placed are called ferromagnetic substances.  Examples:- Iron, cobalt, nickle and a few of alloys

Biat savart's law:- According to the Biot-Savart law, magnetic field dB due to current element dl, at a point P situated at distancer from the current element Idl is: i) directly proportional to the current element Idl.   ii) directly proportional to the sine of the angle (θ) between current element and r,  iii) inversely proportional to the square of the distance r between current element and the point dB∝Idl (sinθ)/r2 dB = (μo/4π)×Idl×(sinθ)/r2 dB = Idl × r / r3

What is magnetism?  The property of a substance to attracting small pieces of iron, steel and some other substances is called magnetism.  Magnet:- The substance which exhibits property of attracting small pieces of iron, steel and some other substances is called magnet. Natural magnet:- The minerals which exhibits property of magnetism are called natural magnets.  Artificial magnets :- Man made magnets convenient for practical purposes are called artificial magnets.  Magnetic poles:- The regions near ends of a magnet where the property of attraction is most prominent are called magnetic poles. Axis  of magnet:- A line joining the poles of a magnet is called axos of the magnet  Magnetic length :- The distance between the true position of length of north and South poles is called magnetic length (NS)  Geometric length :- Length  of a magnet is called it's geometric length. Magnetic dipole and mag...