Question

PROBLEM 4 Locate the points at which (a) V 0 and (b) E 0 + q 3q

Answer 1

Two charges + of and separated by a distance d The electric potential V and the electric field E due to a point charge of at a point located at a distance r from the charge is given by V = K /r and E = k /r^2 i) Now let the point at which V = 0 is A which is x distance from charge of and (d - x) distance from the charge -3 (The zero potential point is considered linearly between two charges becomes potential varies linearly) V times 1/r Let V_1 be potential due to + of at A. V_1 = k /x V_2 = potential due to = 3 at A = -3 k /d - x LEt V_A be total potential deu to a^t A (ZERO) V_A = V_1 + V_2 = 0 V_1 = -V_2 \r\n K /x = 3 k /d - x d = 4x ii) Now, for electric field NULL POINT consider a point B along the charges but outside them (not in between them like I considered before)