Four identical point charges are fixed at the four corners of a square of side

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

Problem

Four identical point charges

+q

are fixed at the four corners of a square of side

a

. A test charge

+q

is placed exactly at the centre of the square. What is the magnitude of the net electrostatic force acting on the central charge? (a)

4k q^{2}/a^{2}

(b)

2\sqrt{2}\,k q^{2}/a^{2}

(c)

0

(d)

2k q^{2}/a^{2}