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# Electron on electric field question watch

1. A pair of flat, square metal plates are held parallel to each other 10cm apart. One is connected to earth, and the other is connected to a 2000V supply.

What difference in effect would there be on electrons placed within the field 1cm apart from the earthed plate, and the other in exact midpoint of the field?

But why?

I think it's because the charge of the electron is very small compared to the 2000V plate that it's negligible.

I'm not sure though if it's correct.
2. (Original post by Alpha-Omega)
A pair of flat, square metal plates are held parallel to each other 10cm apart. One is connected to earth, and the other is connected to a 2000V supply.

What difference in effect would there be on electrons placed within the field 1cm apart from the earthed plate, and the other in exact midpoint of the field?

But why?

I think it's because the charge of the electron is very small compared to the 2000V plate that it's negligible.

I'm not sure though if it's correct.
Electric field strength is constant anywhere inside the field. Hence, the force on an electron is constant regardless of the distance from the plates as long as it is in the field.
3. (Original post by Ari Ben Canaan)
...the force on an electron is constant regardless of the distance from the plates as long as it is in the field.
Isn't the force inversely proportional to the their distance from each other squared? or does that only apply for radial electric fields?
4. (Original post by Alpha-Omega)
Isn't the force inversely proportional to the their distance from each other squared? or does that only apply for radial electric fields?
Exactly. If you want to know why is that, I suggest looking up Gauss's law.
5. (Original post by Alpha-Omega)
Isn't the force inversely proportional to the their distance from each other squared? or does that only apply for radial electric fields?
Remember, in this scenario you are considering a field between two plates. The field (when drawn) would simply be straight lines from one plate to another.
6. (Original post by Ari Ben Canaan)
Electric field strength is constant anywhere inside the field. Hence, the force on an electron is constant regardless of the distance from the plates as long as it is in the field.
E=U/d=2000V/0.1m=20000V/m, electric force F=eE is the same within the two plates.
7. (Original post by Ari Ben Canaan)
Electric field strength is constant anywhere inside the field. Hence, the force on an electron is constant regardless of the distance from the plates as long as it is in the field.
i think the question is why the field is uniform
8. (Original post by blacklistmember)
i think the question is why the field is uniform
Electric field strength = voltage/ separation

Voltage/separation is a constant hence E is equal to this constant (K).

Force on electron = E*charge on electron

Since charge on electron is constant and E = k (see above)

F = K*charge on electron = some constant
9. (Original post by Ari Ben Canaan)
Electric field strength = voltage/ separation

Voltage/separation is a constant hence E is equal to this constant (K).

Force on electron = E*charge on electron

Since charge on electron is constant and E = k (see above)

F = K*charge on electron = some constant
thanks

voltage equals Force*seperation
so its circular
10. (Original post by Ari Ben Canaan)
Electric field strength = voltage/ separation

Voltage/separation is a constant hence E is equal to this constant (K).

Force on electron = E*charge on electron

Since charge on electron is constant and E = k (see above)

F = K*charge on electron = some constant
Thanks!
11. Just found this:

Proof: Field from Uniform infinite plate

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