[Music] normally [Music] is this is the experimental set experimental state of gauri experiment like two women mass of the oil drop mb the mass of the oil drop this is called row row is density of the wind sigma 1 okay density of the air lamina 1 so the sigma 1 this is the density of the well this is density total foreign density oh into your g channel volume one ago four by three pi r cube volume into density of weld into your gravity kiwi with uh weight of the wheel drop i o over 4 by 3 pi r cube into density of air into gravity of thrust calculated [Music] conical examination sigma g and weight of the wheel drop is four by three pi r cube uh rho into g bar right rho into g minus 4 by 3 pi r cube sigma equation g y y 6 pi eta r v 1 is equal to 4 by 3 common python v1 is equal to 4 by 3 pi r e square g rho minus k by sigma y hey pi r square z rho minus sigma pi cancel y r e square is equal to 18 eta v1 divided by 4 g row minus sigma [Music] r is equal to 9 2 right 2 2 4 9 to the 18 r is equal to root over 9 eta v 1 divided by twice g row minus sigma this is the value of radius radius radius uh motion of will drop under the effect of gravity only error right gravity membrane radius of the wheel drop our in the next step i make also money under the effect of both right electric field and gravity guard obviously a strong electric field is applied between the plates in such a direction that force on the negatively charged will drop right well drop k ones are negatively charged ah due to the electric fields acts in vertical vertically upward direction your vinegar q1a of upward direction right now the wheel drop starts moving in upward direction over you will drop like a plate electrical positively negative move [Music] upward force equals to sum of downward force simply a concept linear theory hey sum of upward force equal to sum of downward forces as we know right total upward force one equal u plus f e is equal to f plus w of f simple electric field [Music] alone is equal to downward force f plus u is equal to question right gravity alone f is equal to w minus for events f q is equal to 6 pi eta b1 plus b2 divided by e into k1 number 1 here q is equal to 6 pi eta p1 plus p2 this is required expression to find out total charge on the oil drop your q one okay y total charge on the wheel drop already considered java electric field of like original plate money to changes if electric field is not strong enough to create motion of oil drop in upward direction then minus b2 divided by e into 9 eta v1 divided by 2z rho minus sigma your formula usually if oil drop is falling downward right downward facility your formula of like auto personnel a millions of drop experience results q is equal to 6 pi eta b1 plus minus b2 divided by e into nine eta b1 2g uh rho minus k sigma yeah plus minus direction operator plus linear direction downward minus foreign always 1.6 into 10 to the power minus 19 co multiple ma okay total charge your total charge on the oil drop a 1 into one point six into ten to the power minus nineteen i could total charge hey experiment repeat guard two into one point six minus ten to the power minus nineteen iola or sodium into 10 to the power minus nineteen months but there is always in the multiple of one point six into ten to the power minus nineteen cola your experimenter repeats drop is integral multiple of electronic [Music] into 10 to the power minus 19 1.6 into 10 to the power minus 19 this is the value of charge of an electron your electron cook you charge by okay sorry calculated your experimental repetition charge of the electronic [Music]