Answer:
Other charge is given as
[tex]q = 0.20 \mu C[/tex]
Explanation:
Work done to bring the two charges from infinite large to finite distance is given as change in potential energy of the system of two charges
[tex]W = U_2 - U_1[/tex]
here we have
initial potential energy must be zero as it is infinite distance away initially
[tex]U_1 = 0[/tex]
now we have final energy as
[tex]U_2 = \frac{kq_1q_2}{r}[/tex]
[tex]U_2 = \frac{(9\times 10^9)(35\mu C)(q)}{(3 - 1)\times 10^{-3}}[/tex]
[tex]U_2 = (1.57\times 10^8)q[/tex]
now from above formula
[tex]32 = (1.57\times 10^8)q - 0[/tex]
[tex]q = 0.20 \mu C[/tex]