Year of Inventions

8/13/2019 Year of Inventions

1/9

Year Name of thCountry Invention

1850 Geissler German If air is removed from a glass tube, it glows when an electric current

1878 Sir Willian British Current in vaccum tubes seemed to consists of particles

1890 Perrin French Current in vaccum tubes consists of negatively charged particles.

Thomson British Negatively charged particles measured

1909 Milikan American Charge of an electron

1904 Fleming Invented a Felming valused to detect Electromagnetic waves1907 Lee de For American Invented a triode vaccum tubes used in oscillator circuits

1915 Triode used in oscillator circuits and telephone instruments

1916 German Tetrode

1926 Dutch Pentode

1920 American First television picture tube called kinescope

1939 British Magnetron

1939 American Klystron microwave tubes

1943 American Travwelling wave tube(TWT)

1947 Walter Brit Year of Sol Bell Labs

1951 Commerci RCA, Raythesn, General Electric, Westing house , Wester

1958 germanium and silicon can be used to create a entire circuit called m

1959 Noyce Multiple devices in a single piece of silicon

1960 Use of vacccum tubes become obsolute replaced by BJT an FET

1961 Fairchild and Texas ins IC's manufactured

1961 SSI-Small scale integration- no of components fabricated on a single

1966 MSI- No. of components fabricated on a single chip was 100-1000

1970 LSI-no of components fabricated in a single chip is between 1000-10

1980 VLSI- no of components which can fabricate about 1 million or more


2/9

asses through it

Electric were the first to fabricate transistors.

onolithic - monolithic circuit was named as IC

hip less than 100

000

components on a single chip


3/9

GaAr Gallium Arsenide- used for fabrication of IC's

Thyratron gas filled tube

Si, Ge, GaAs follows tetrahedral or diamond lattice/Zine blends lattice

Ne,He,Krypton,Argon are noble gases or inert gases since the valence shell is complete.

Ionic bond is otherwise called as electrovalent bond

Primary bonds are ionic bond, covalent bond and metallic bond.

secondary bond are weak bonds.ionic bond readily form between alkalimetals and halogen atoms

ionic bod has high boiling and melting points.

ionic bods are bad conductors of electricity in solid state and good conductors of electricity in molten st


4/9


5/9

DMM Digital Multimeter

SCR Silicon controllede rectifier

MRI Magnetic Resonance Imaging

SCR Simple Cubic

BCC Body centred Cubic

FCC Face Centred Cubic


6/9

Crystal lattiArranvgement of atoms in solid

Non-crystalline or amorphous


7/9

1.6x10^ -19 C Electron charge

9.1x10^ -31 kg Mass of an electron

1840*9.1x10^ -31kg Mass of neutron and mass of proton

2n^ 2 no fo electrons in each shell(namely K,L,M,N)

6.626x10^ -34 Joules Plancks constant h

1.602 x 10^ -19 1 eV


8/9

E=hf E-energy in quanta, h-planks constant, f- frequency of rai

W2-W1= hf(in joules) W2- Energy of the final orbit, W1- energy in the initial orb

Wn= -21.76x10^ -19 (Z^2/n^2)(in Joules) Z-atomic number, n-orbit, w- energy possessed by an ele

1 eV= 1.602 x10^-19

En= Wn/1 eV or =(-21.76 x 10^ -19x(Z^2/n^2))/1.6 x 10^ -19 = -13.6x (z^2/n^2)(in electron volts)

W0 Bond energy(kJ/mole)


9/9

tion: h-planks ocnstant= 60626x10^ -34 Js

it, h- planck's constant, f- frequency of radiation

tron

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Year of Inventions