Answer:
Explanation:
Let E be the strength of electric field and m be the mass of plastic sphere.
charge on plastic sphere, q = - 3 n C = - 3 x 10^-9 C
The force due to electric field on the charged plastic sphere = q E
The weight of the plastic sphere = m g
where, g is the acceleration due to gravity.
Now the force due to electrostatic field is balanced by teh weight of the plastic sphere.
q E = m g
E = m g / q
E = m x 9.8 / (3 x 10^-9) = 3.26 x 10^9 x m
Substitute the value of m and get the value E.
