, qn We can use Coulomb’s law and the
superposition principle to determine this field at a point P denoted by
position vector r Rationalised 2023-24
16
Physics
Electric field E1 at r due to q1 at r1 is given by
E1 = 
41
0
1
1
2
πε
q
r P
1P
ˆr
where 
1P
ˆr  is a unit vector in the direction from q1 to P,
and r1P is the distance between q1 and P In the same manner, electric field E2 at r due to q2 at
r2 is
E2 = 
41
0
2
2
2
πε
q
r P
2P
ˆr
where 
ˆr2P
 is a unit vector in the direction from q2 to P
and r2P is the distance between q2 and P