HOw to calculate the number of electrons from a given battery capacity

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SUMMARY

The calculation of the number of electrons flowing through a battery with a cell capacity of 3.5 A.h over 30 minutes involves using the formula Q = I.t. By converting 30 minutes into seconds (1800 seconds) and applying the formula, the total charge (Q) is calculated as 6300 Coulombs. Dividing this charge by the elementary charge (1.6 x 10^-19 Coulombs) results in approximately 3.94 x 10^22 electrons. This method emphasizes the importance of unit conversion for accurate calculations.

PREREQUISITES
  • Understanding of electric charge and current
  • Familiarity with the formula Q = I.t
  • Knowledge of elementary charge (1.6 x 10^-19 Coulombs)
  • Basic unit conversion skills (seconds to hours)
NEXT STEPS
  • Study the concept of electric charge in detail
  • Learn about the relationship between current, charge, and time
  • Explore advanced calculations involving capacitors and batteries
  • Investigate the implications of electron flow in different circuit configurations
USEFUL FOR

Students in physics or electrical engineering, educators teaching basic electricity concepts, and anyone interested in understanding battery capacity and electron flow calculations.

Clark Kent
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Homework Statement



If the cell capacity of a cell is 3,5A.h; calculate the number of electrons that flow through the cell in 30 minutes.


Homework Equations


Q= I.t


The Attempt at a Solution


Q= I.t
= 3.5x(1800)
= 6300C

6300/(1.6 x 10^-19)
= 3.94 x 10^22 electrons
 
Physics news on Phys.org
well, one definition of the amp, although not the right one, is that 6x10^18 (forgive me if my numbers are wrong because i don't have a calc right now, but you can get this number from the elementary charge e) flow through in unit time (1s).
If capacity is 3.5Ah, then convert the 30 minutes to hours, multiply that by 3.5Ah, and then use the relationship q=Ix(change in time).
However a better way to do this would be to convert the minutes into seconds, as well as 3.5Ah to As(ampere seconds) and then do the calculation.
 

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