Question

A positive point charge (q = +8.65 x 10-8 C) is surrounded by an equipotential surface A, which has a radius of rA = 2.97 m. A positive test charge (q0 = +4.56 x 10-11 C) moves from surface A to another equipotential surface B, which has a radius rB. The work done by the electric force as the test charge moves from surface A to surface B is WAB = -6.95 x 10-9 J. Find rB.

Answer 1

`r_B = 1.88 m`

Step-by-step explanation:

As we know that work done by electric force is given as

`W_e = -q\Delta V`

so here we know that charge is moving from

`r_A = 2.97 m`

to another position

so we will have

`W_(AB) = (kq_1q_2)/(r_A) - (kq_1q_2)/(r_B)`

`-6.95* 10^(-9) = (9* 10^9)(8.65* 10^(-8))(4.56* 10^(-11))((1)/(2.97) - (1)/(r_B))`

`-0.196 = ((1)/(2.97) - (1)/(r_B))`

`r_B = 1.88 m`