A point charge q is situated at a distance d (point A) from an infinite conducti

Question

A point charge q is situated at a distance d (point A) from an infinite conducting plane with charge distribution ?. (a) Find the work done by the electric force in moving the charge from point A to point B (at distance r). (b) Assume that the infinite conducting plate is grounded and there is no additional charge distribution. The only charge the plate can have is the induced charge due to the point charge q. Calculate the work done by the electric force in moving the point charge from point A to point B in this changed scenario. (it says for a hint to use method of images on part b)

Explanation / Answer

potential due to a charged sheet at a distance r from sheet

v = sigma*r/2*eo

potential at A vA = sigma*d/(2*eo)

potential at B vB = sigma*r/(2*eo)

work done W = (vB-vA)*q

W = sigma*(r-d)*q/(2*eo)

+++++++++

b)

charge on sheet = -q

at d seperation energy U1 = -k*q*q/d = -k*q^2/d

at r seperation energy U21 = -k*q*q/r = -k*q^2/r

work done = U2-U1 = -k*q^2/r -k*q^2/d

W = -k*q^2*(1/r + 1/d)

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.