Find out electric field intensity at point A (0, 1m, 2m) due to a point charge `-20 muC` situated at point `B (sqrt(2)m, 0, 1m)`.

Explanation

`E=(KQ)/(|vec(r)|^(3))vec(r)=(KQ)/(|vec(r)|^(2))vec(r) implies vec(r)=P.V.` of `A-P.V.` of B (P.V. = Position vector)
`=(-sqrt(2)hat(i)+hat(j)+hat(k))|vec(r)|=sqrt((sqrt(2))^(2)+(1)^(2)+(1)^(2))=2`
`E=(9xx10^(9)xx(-20xx10^(-6)))/8(-sqrt(2)hat(i)+hat(j)+hat(k))=-22.5xx10^(3) (-sqrt(2)hat(i)+hat(j)+hat(k))N//C`