Current in DC Circuit: 8.41 x 10^19 Electrons in 2s

  • Thread starter Thread starter jst
  • Start date Start date
  • Tags Tags
    Circuit Current
AI Thread Summary
In a DC circuit, 8.41 x 10^19 electrons pass through a point in two seconds, leading to the calculation of current. The correct formula to find current is the total charge divided by time, where the charge is derived from the number of electrons and the charge of a single electron (1.602 x 10^-19 coulombs). After calculations, the current is determined to be approximately 6.75 amps. The discussion highlights the importance of converting electron count to charge before calculating current in amperes. The final result aligns with expected solutions, confirming the accuracy of the approach.
jst
Messages
28
Reaction score
0

Homework Statement



In a DC circuit 8.41 x 10^19 electrons travel through a point in the circuit in two seconds. What current is in the circuit?

Homework Equations

I'm not sure at all on this. I was thinking it would be something like (charge*#electrons)/time, but I don't have a value for the charge

The Attempt at a Solution



Would it possibly be: (6.241 509 629 152 65×10^18 * 8.41 x 10^19)/2Thanks,

Jason
 
Last edited:
Physics news on Phys.org
6.241 509 629 152 65×10^18

This is how many electrons are needed for one coulomb of charge. What you want is to find the charge of one electron, if you are going to use your equation the way it is.
 
As I understand the problem you need to convert the number of electrons to amperes. The ampere is a coulomb/sec and 1 electron is 1.602e-19 coul. I get 6.75 amps.
 
1 ampere is 6.24x1018 electrons passing a point in a second. Since you know how many pass in two seconds you need to divide half the number given in the question by the number given in the definition.

EDIT: All posted in the same minute and I'm last :rolleyes: Figures
 
Thanks to everyone! It's funny, I think I might have figured out before reading your posts.

See what you think:

=((# of electrons)*(charge of electron))/time

=
((8.41*10^19)*(1.6*10^-19))/2

=6.728


...at least it maches up with one of the possible solutions :)

Thanks again,

Jason
 
It was right...big thanks to everyone.

Jason
 
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
I was thinking using 2 purple mattress samples, and taping them together, I do want other ideas though, the main guidelines are; Must have a volume LESS than 1600 cubic centimeters, and CAN'T exceed 25 cm in ANY direction. Must be LESS than 1 kg. NO parachutes. NO glue or Tape can touch the egg. MUST be able to take egg out in less than 1 minute. Grade A large eggs will be used.
Back
Top