Which one of the following expressions gives the electric potential at a point due to…

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

Problem

Which one of the following expressions gives the electric potential

V

at a point

P

due to three point charges

q_1,\,q_2,\,q_3

kept at distances

r_1,\,r_2,\,r_3

respectively from

P

? (a)

V = \dfrac{1}{4\pi\varepsilon_0}\left(\dfrac{q_1}{r_1^{2}}+\dfrac{q_2}{r_2^{2}}+\dfrac{q_3}{r_3^{2}}\right)

(b)

V = \dfrac{1}{4\pi\varepsilon_0}\left(\dfrac{|q_1|}{r_1}+\dfrac{|q_2|}{r_2}+\dfrac{|q_3|}{r_3}\right)

(c)

V = \dfrac{1}{4\pi\varepsilon_0}\left(\dfrac{q_1}{r_1}+\dfrac{q_2}{r_2}+\dfrac{q_3}{r_3}\right)

(d)

V = \dfrac{1}{4\pi\varepsilon_0}\sqrt{\left(\dfrac{q_1}{r_1}\right)^{2}+\left(\dfrac{q_2}{r_2}\right)^{2}+\left(\dfrac{q_3}{r_3}\right)^{2}}