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The intensity of the electric field requ...

The intensity of the electric field required to keep a water drop of radius `10^-5` cm just suspend in air when charged with one electron is approximately.

A

(A) 130V/cm

B

(B) 26V/m

C

(C) 130 N/C

D

(D) 260 N/C

Text Solution

Verified by Experts

The correct Answer is:
D
F=Ee
mg =Ee
`therefore E = (mg)/e = (4/3pi^(2)rhog)/e`
`=(4 xx 3.14 xx (10^(-7))^(3) xx 10^(3) xx 9.8)/(3 xx 1.6 xx 10^(-19))`
`=25.643 xx 10^(1) = 256`
= 260 N/C (Upto two significant numbers)
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