Curious

 Semiconductor Materials: Ge, Si, And GaAs The construction of every discrete (individual) solid-state (hard crystal structure) electronic device or integrated circuit begins with a semiconductor material of the highest quality.  Semiconductors are a special class of elements having a conductivity between that of a good conductor and that of an insulator.  In general, semiconductor materials fall into one of two classes: single-crystal and compound.  Single-crystal semiconductors such as germanium (Ge) and silicon (So) have a repetitive crystal structure, whereas compound semiconductors such as gallium arsenide (GaAs),  Cadmium sulfide (CdS), gallium nitride (GaN), and gallium arsenide phosphide (GaAsP) are constructed of two or more semiconductor materials of different atomic structures.  The three semiconductors used most frequently in the construction of electronic devices are Ge, Si, and GaAs.  In the first few decades following the discovery of the diode in 1939 and the transistor

  Hey friends, In this blog you will understand what are conductors and insulators, what is earthing or grounding, what is electrostatic induction and how we can charge a sphere by induction process.  Conductors and insulators Conductors -  The substances through which electric charges can flow easily are called conductors.  The conductors contain a large no. Of free electrons which make then good conductor of electricity.  For ex - silver, copper, aluminum, human, animal bodies, acids, graphite etc.  Insulators - The substances through which electric charges can not flow easily are called insulators.  Free electron is tightly bond with the nucleus in it so there is an absence of free electrons the insulators can not conduct electric charges.                                  Note A metal rod held in hand and rubbed with wool not developed any charge ( the charge developed on the metal rod is transferred to the earth through the human body) , we can electrify the rod by providing it a p

In this blog you will understand what is frictional electricity, electric charge, electrostatic, application of electrostatic and Electronic theory of frictional electricity.  Frictional electricity If a glass rod is rubbed with a silk cloth it is able to attract small pieces of paper, light feathers, etc.  Similarly, a plastic comb passed through dry hair can attracts such light objects.  In all these examples we can say that the rubbed substance has become electrified or electrically charged (the property of rubbed substances due to which they can attract light objects is called electricity) .  Electric charge It is the inherent propertie pf elementary particles of the matter which gives rise of electric forces due to other charge particles.  For ex - charge on electron is given by -e and charge on proton is given by +e where the value of "e" Is given by e = 1.6 × 10(of power of -19) coloumb.  • The SI unit of electric charge is coloumb (C).  • Generally in the massive bodi

             Polarisation The phenomenon of restricting the waves in oscillation to particular plane is called polarisation.                             Note A wave having oscillation in all possible direction is said to be polarised.  When the all oscillation get can fined along one direction the wave is called plane polarised.  Representation of Unpolarised and polarised Pictorial representations of Unpolarised light Plane polarised light: (a) vibrations parallel to the plane of paper. (b) vibrations perpendicular to the plane of paper.  Experimental demonstration of polarisation Intensity depends upon the angle between polariser axis and analyser axis.  Law of molus It States that the intensity of polarised light transmitted through the analyser varies as the square of cosine of the angle between the plane of transmission of analyser and polariser.                               Or Angle between optical axis of analyser and polariser.  I is directly proportional to cos(theta) × cos(t

Principle of Superposition of wave It states that if the no. Of waves travelling in the same direction in a medium then the total displacement of the resultant wave is given by vector sum of displacement of all individual waves  Interference of wave                                 when the 2 wave of same frequency and having zero or constant phase difference propagates in same direction superposed on each other then the intensity of resultant wave having minimum and maximum values at the particular point in the medium. This phenomenon is known as interference of wave.                                    Note • the points at which the intensity of resultant wave is maximum is known as constructive interference.  • the points at which the intensity of resultant wave is minimum is called destructive interference.  Young's double slit experiment Young's obtained interference pattern on the screen.                                      Note • At where crest - crest or trough - trough

   Huygens principal According to this principal the particles on wave front behaves like fresh source of light emit waves in all direction called secondary wavelets and the envelop (tangential surface) in the forward direction to the secondary wavelets gives the new position of wavefront in the medium.     Construction The light ray passes normally through the wave front and the disturbance propagates with the direction of speed of light in the medium If disturbance taken 't' time to reach from AB to PQ It covers,                    d = c × t       Where, d = distance from AB to PQ Now on drawing sphere of radius ct around particle in PQ  Then the tangential surface on sphere in forward direction gives a new position A forward wave front.  Laws of reflection from Huygen's principal If wavefront taken 't' time from B to C with 'v' velocity        BC = vt Taken and arc of radius of vt and draw tangent on it from C.  Law of refraction From triangle ABC    Sini