15 m)
E
−
×
×
=
=  4 × 103  N C–1
The magnitude of the total electric field at B is
EB = E1B –  E2B = 3 2 × 104 N C–1
EB is directed towards the left The magnitude of each electric field vector at point C, due to charge
q1 and q2 is
     
9
2
–2
8
1C
2C
2
(9
10 Nm C
)
(10
C)
(0 10 m)
E
E
−
×
×
=
=
 =  9 × 103  N C–1
The directions in which these two vectors point are indicated in
Fig