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An oil drop of 12 excess electrons is he...

An oil drop of 12 excess electrons is held stationaty under a constant electric field of `2.55xx10^(4) NC^(-1)` in Millikan's oil drop experi,ment. The density of the oil is `1.26 g cm^(-3)`. Estimate the radius of the drop. `(g = 9.81 ms^(-2) , e = 1.60xx10^(19) C)`

A

`10^(18)`

B

`10^(15)`

C

`10^(6)`

D

`10^(12)`

Text Solution

Verified by Experts

The correct Answer is:
D
`qE=mg implies q = (1.6 xx10^(-6) xx10)/(100) =1.6 xx10^(-7)C`
`n=q/e = (1.6 xx10^(-7))/(1.6 xx10^(-19))=10^(12)`
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