Question

A Charge O -884 nC is uniformly distributed on a ring of 2.4 m radius. A point charge q = +567 nC is fixed at the center of the ring, Points A and B are located on the axis of the ring, as shown in the figure. What is the minimum work that an external force must do to transport an electron from B to A? 1.4 m Select one: 2. 3.00-16) O b. 1.40-17) c.-1.86-16) d.-9.20-173 9.-2.90-16) d ichacontando cochond. .checondo com

Answer 1

1.8 A 1.4 B The radias of the ring a= 219 m charge is uniformly distributed along the ring Charge & Q = - 889 ne The charge per unit length along the ring a 2 na The potential due to small element on the ring at a distance x from the center too dv = 19 = ax do 4RE0 5x² 22 rox²+Q2 dq=hado The total potential oor- at do 476 auto ] Jaraz = ax 2 - 426 2²7 22 426 4242² The potential at point A due to charge ring . - 884nc. I =9x10 ARE (1.8) (2.92 = - 884x16x9x109 =-2652 AM J/c √1.82 +2142 The potential at point B due to change ring 121.8t 1.463-2 4260 of (131 23²+ (2.922 = - 1989 on Ilc Potential at point A due to positive charge q = + 567 ne - 5678159 40608 = = 2835 /c 126 x 1.8 - The potential at point B due to a charge at Centre - 567x109 = 1594.69 T/C 4T6.03.2 - - 884x109

- 2652 Total potential sat T/C 650.000 point A = + 2835 = 183 J/ Total potential at point B, w = -1989 + 1594.69 J/ = -394.31J/C The energy due to electron at point ave I A =V9 9=0 se=11641619 € The energy due to electron at point B = Ve I The energy required to transport electron from a to A W = (coupe-VAC) I - (vo-VA) e J = (-394.31 +/83) X-16x10-19 - (394.31 +183) *16*10-19, = 9.24x10-17 g Am. option (d) in correct.