Point charges (at ) and (at ) are separated by in air

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

Problem

Point charges

+5\,\mu\text{C}

(at

A

) and

-20\,\mu\text{C}

(at

B

) are separated by

AB = 40\,\text{cm}

in air. Along the straight line

AB

, measured from

A

, at what position will a small positive test charge experience zero net electrostatic force? (a)

13.3\,\text{cm}

from

A

towards

B

(b)

13.3\,\text{cm}

on the side of

A

away from

B

(c)

40\,\text{cm}

on the side of

A

away from

B

(d) No finite position exists