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 )|)vec(r ) = (KQ)/(|vec(r )|^(2)) hat(r )`
`rArr 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((sqrt2)^(2)+(1)^(2)+(1)^(2)) = 2`
`E = (9 xx 10^(9) xx (-20 xx 10^(-6)))/(8) (-sqrt(2)hat(i) + hat(j) + hat(k))`
`= -22.5 xx 10^(3)(-sqrt(2)hat(i) + hat(j) + hat(k))N//C`.