2009年6月16日 · This formula is only valid for point charges. The formula [itex]W=qEd[/itex] is the work needed to move a charge q in an electrical field E a distance d. The general formula is W=qV, for a uniform electrical field V=Ed. Therefore you can only use W=qEd for a point charge in a uniform electrical field.

2008年3月27日 · I think W = qV is more for moving just one or a set number of charges across a voltage difference V (ie a capacitor) while W = 1/2QV is the work required to fully charge, or move ALL of the charges, across a capacitor to fully charge it

2008年7月31日 · Yes, but you could have written it as W = qV where V is the positive potential difference and the minus sign is due to the fact we are looking from the perspective of the field and not the amount of work we must do to move the charge.

2018年2月25日 · Hi I have a question about electric potential! Since the negative sign isn't used in U=qV, and a-b is used for subscripts, then that takes care of the negative. But what about using U=-qV? An online lecturer uses U=-qV, while my textbook uses U=qV and then uses -qV to explain the force used to...

2010年5月2日 · I do not understand what determines whether I should use one formula or the next. In the case of a charge moving from one pole to the other via a dialectric. Is it because it is a single charge I thus use "PE=qV" whereas if i was moving the entire dialectric then it would be PE = 1/2(QV). That...

2018年6月27日 · when calculating the work done in a uniform electric field on a positive charge to move it from point a at higher potential to point b at lower potential that means the charge is going towards the negative plate we first use V = - ED and then we have a negative V then we use W = qv and we have a negative work that means the work is done by the ...

2013年2月23日 · Hi guys, I'm doing TPR physics problems and having some difficulties understanding this concept: 1) How much work must be done to move a -2 coulomb charge from the positive plate to the negative plate of a capacitor charged to 10V. Answer: they use W=Q*change in V, yielding the...

2012年4月26日 · The energy stored on a charged capacitor is 0.5*Q*V or 0.5*C*V2 BUT what is the electrical work done by the supply as it transfers the charge to the capacitor? I have heard two answers: W=QV and W=0.5*QV the first answer implies, i think, that energy is required to move charges against...

2013年4月3日 · I shouldn't have really mentioned the Emf = I(R+r) equation. This doesn't confuse me, I just included it because it was grouped with the V=W/Q and Emf = E/Q equations in the data sheet.

2015年5月21日 · Homework Statement A charged particle is moved from a great distance to a distance d from a point charge. At distance d, the electric field has a strength E and a potential V. Which of the following represents the work done per unit charge q? Homework Equations F = Eq; V = Ed, E = kq/r^2; U...