Two Charged spheres of 6.4 nC charge are 16 cm apart. What is the magnitude of the field in middle? (n = 10^-9, 100 cm = 1 m)

zero

Explanation:

q = 6.4 nC = 6.4 x 1 0^-9 C

d = 16 cm = 0.16 m

r = 16 / 2 = 8 cm = 0.08 m

Electric field at P due to the charge placed at A

Ea = k q / r^2

Ea = (9 x 10^9 x 6.4 x 10^-9) / (0.08 x 0.08) Towards right

Ea = 9000 Towards right

Electric field at P due to the charge placed at B

Eb = k q / r^2

Eb = (9 x 10^9 x 6.4 x 10^-9) / (0.08 x 0.08) Towards left

Eb = 9000 Towards left

The magnitude of electric field is same but teh direction is opposite, so the resultant electric field at P is zero.