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How many electrons pass through a lamp in one minute if the current be 200 mA?  

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zorkin | Student, Grade 10 | eNotes Newbie

Posted June 1, 2013 at 5:43 AM via web

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How many electrons pass through a lamp in one minute if the current be 200 mA?

 

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justaguide | College Teacher | (Level 2) Distinguished Educator

Posted June 1, 2013 at 6:00 AM (Answer #1)

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A current of 200 mA is flowing through the lamp. One ampere is the current that flows through the lamp when one coulomb of charge passes in one second. The charge of an electron is 1.602*10^-19 C.

The number of electrons that pass through the lamp in one second is equal to `(200*10^-3)/(1.602*10^-19)` . The number of electrons that pass through the lamp in one minute is equal to `(200*10^-3*60)/(1.602*10^-19)` = `7.49*10^19` .

Another way of determining this is to use the fact that one ampere is current that flows when `6.241*10^18` electrons pass through in one second. This gives the number of electrons passing through the lamp in a minute as `6.241*10^18*60 = 7.48*10^19`

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