Three point charges are fixed at the corners of a rectangle: at

PHYSICS · Multi-part · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

Three point charges are fixed at the corners of a rectangle:

+2\,\mu\text{C}

P(0,0)

+2\,\mu\text{C}

Q(6\,\text{cm},0)

and

-3\,\mu\text{C}

R(0,8\,\text{cm})

. Evaluate the electric field at the fourth corner

S(6\,\text{cm},8\,\text{cm})

. (i) Calculate the components

E_x

and

E_y

S

. (ii) Hence find the magnitude of the field and the angle it makes with the positive

x

-axis.