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Electric current, charge, and flow of charge

Free Homework Help!PhysicsElectric current, charge, and flow of charge

Muhammed Amjad
asked 8 months ago

29. A total of 20.0 Coulombs of charge pass through a given point in a conductor 4.0s. Calculate the current in the conductor.

30. A wire carries a current of 2 Amperes. How many electrons pass a given points in 1.0s?

31. Which condition must exist between two points in a conductor in order to maintain a flow of charge?

1 Answers
Alexander Chioma Staff answered 8 months ago

Hello! Thank you for the question.
29. The current in the conductor is given by:  I = q/t
In this case we get I = 20.0C / 4.0s = 5C/s or 5A
30. For the amount of electrons that pass a single point in one second we use the same formula I = q/t
In this case we use q = ne to replace the q and get I = ne/t
By multiplying both sides by t/e we can solve for the number of electrons: n = It/e
e is the charge of an electron which is equal to -1.6×10^-19C (This will usually be given on a test)
When we plug in our given values we get n = 2.0A (1s) / 1.6×10^-19C = 1.25×10^-19 electrons. The closest answer for you would be (3)
31. In order to maintain a flow of electrons between two points in a conductor, they must have (1) a potential difference. 

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