Answer:
The charge on the bead is

Step-by-step explanation:
From the question we are told that
The mass of the bead is

The magnitude of the electric field is

The acceleration of the bead is

Generally, the electric force on the bead is mathematically represented as

Where q is the charge on the bead
Now the gravitational force opposing the upward movement of the bead is mathematically represented as

Generally the net force on the bead is mathematically represented as

=>

Now substituting values

