An oil drop of radius 2 mm |Electrostatics| JEE MAIN 2021

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JEE MAIN 2021

18-03-21 S1

Question

An oil drop of radius 2 mm with a density $3 \mathrm{~g} \mathrm{~cm}^{-3}$ his held stationary under a constant electric field $3.55 \times 10^5 \mathrm{Vm}^{-1}$ in the Millikan's oil drop experiment. What is the number of excess electrons that the oil drop will possess ? (consider $\mathrm{g}=9.81 \mathrm{~m} / \mathrm{s}^2$ )

Select the correct option:

A

$48.8 \times 10^{11}$

B

$1.73 \times 10^{10}$

C

$17.3 \times 10^{10}$

D

$1.73 \times 10^{12}$

✓ Correct! Well done.

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Solution

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