A point charge is kept at the origin

PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

A point charge

+1.0\,\mu\text{C}

is kept at the origin. Two other point charges are kept at

(3.0\,\text{m},0)

and

(0,4.0\,\text{m})

having magnitudes

+3.0\,\mu\text{C}

and

-4.0\,\mu\text{C}

respectively. Find the magnitude of the net electrostatic force acting on the charge at the origin. Take

k = 9.0 \times 10^{9}\,\text{N m}^{2}\text{C}^{-2}

. (a)

0.75 \times 10^{-3}\,\text{N}

(b)

5.25 \times 10^{-3}\,\text{N}

(c)

3.75 \times 10^{-3}\,\text{N}

(d)

3.0 \times 10^{-3}\,\text{N}