Two point charges of are placed at and on the -axis

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

Problem

Two point charges of

+4\,\mu\text{C}

are placed at

(0,\,+0.30\,\text{m})

and

(0,\,-0.30\,\text{m})

on the

y

-axis. A test charge of

+2\,\mu\text{C}

is kept at

(+0.40\,\text{m},\,0)

. Taking

k = 9 \times 10^9\,\text{N m}^2\!\text{/C}^2

, the

x

-component of the net electrostatic force on the test charge is closest to (a)

+0.92\,\text{N}

(b)

+0.23\,\text{N}

(c)

+0.46\,\text{N}

(d)

-0.46\,\text{N}