Two positive point charges and are fixed apart in vacuum

PHYSICS · Single correct · AP · Physics 2: Algebra-based · Electric Force Field and Potential · Electric Force Field and Potential

Problem

Two positive point charges

+4\,\mu\text{C}

and

+9\,\mu\text{C}

are fixed

30\,\text{cm}

apart in vacuum. At what distance from the

+4\,\mu\text{C}

charge, measured along the line joining the charges, is the electric field zero? (a)

18\,\text{cm}

(b)

24\,\text{cm}

(c)

12\,\text{cm}

(d)

9\,\text{cm}