In Milikan’s experiment, static electric charge on the oil drops has been obtained by shining X-rays. If the static electric charge on the oil drop is –1.282 × 10–18C, calculate the number of electrons present on it.


Given:

Charge present on oil drop = –1.282 × 10–18 C


Charge of one electron = 1.6× 10-19 J


Charge on oil drop, = ne


Where


n = number of electrons


e = 1.6× 10-19 J


n = [–1.282 × 10–18 C] / [1.6× 10-19]


n = 8 electrons


Therefore, the number of electrons present on oil drop is 8 electrons.


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