Discharging of a capacitor through a light bulb.

[smahapatra3]

Homework Statement

Which of the following statements about the discharging of a capacitor through a lightbulb are correct?

a. Electrons in the wires flow away from the negative plate, toward the positive plate, reducing the charge on the plates.
b. The electric field at a location inside the wire is due to charge on the surface of the wires and charge on the plates of the capacitor.
c. Electrons flow across the gap between the plates of the capacitor, thus reducing the charge on the capacitor.
d. The fringe field of the capacitor decreases as the charge on the capacitor plates decreases.

Homework Equations

None.

The Attempt at a Solution

Electrons flow toward the positive plate so I think a is correct. The net field inside the wire should be zero so b is not correct. Electrons cannot flow through air so c is incorrect. And I think d is correct as well. I put in a and d and got it wrong. I also put in only d and that was wrong also.

 

[tiny-tim]

welcome to pf!

hi smahapatra3! welcome to pf!

The net field inside the wire should be zero so b is not correct.

ah, you're thinking that the electric field inside a conductor is always zero,

but that only applies in the static case …

if you move a charged rod near an uncharged metal sphere, the charges in the sphere will extremely quickly rearrange themselves so as to cancel the field from the rod inside the sphere …

but while they are rearranging themselves, there is a field

(and there is always a field in a current-carrying wire)

 

[smahapatra3]

thank you! i forgot to keep in mind that this is not a static situation.