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unit1 viva

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 > Hall effect discovered by Edwin Herbert Hall in 1879. 18 years before electron. >when current is passed in a conductor and then the magnetic field is passed both being perpendicular then a voltage diff is generated due to Lorentz force which is perpendicular to both magnetic field and current this is called hall voltage. >Gauss meter with Gauss Probe can measure both intensity and direction of the magnetic field. >Current source is a power generator whose internal resistance is very high compared to load resistance and it supplies constant power current to load resistance even when load resistance changes over a wide range. >Devices that are used to measure magnetic fields are called Hall probes. It has 4 collinearly placed pins. Current is measured between outer probes and voltage between inner probes. >In this experiment current and voltage stay below some threshold. > hall coefficient is positive for P-type and negative for N-type and 0 for intrinsic. ...

FERMI DIREC FUNCTION

 IF FUNTION HAVE VALUE 0(0% probablity of finding electron above fermi level)

EXP-2

 if material is germanium  then  current - 3mA Range current - 20 mA Range oven - 1 Range voltage = 100mV range if material is silicon then  current - 3mA Range current - 20 mA Range oven - 1 Range voltage = 1V or 10V range

EXP_1

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UNIT_1_CHAPTER_1_LECTURE_2

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 >> To calculate miller indices first write the number then take reciprocal of it and then multiply it by LCM of all the numbers and then solve and find the answer. >> bar on 6b means it is in -ve axis >> family is set of planes. >> drawing plane when miller indices are greater than 1

UNIT_1_CHAPTER_1_LECTURE_1

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