What are the diameters of the disks?

Question

Two circular disks spaced 0.50 mmmm apart form a parallel-plate capacitor. Transferring 1.30 x10^9×109electrons from one disk to the other causes the electric field strength to be 3.10 x10^5 N/C×105N/C.

Answer 1

Step 1:

The electric field strength between the two circular disks is .

Number of electrons transferring from one plate to another .

Total Charge , where

is the number of electrons.

is the electron charge().

Step 2:

Find the total charge on the two circular disks.

Total charge , where

is the capacitance of the two circular disks .

is the voltage across the two circular disks .

Here is the area of the circular disks .

is the permittivity of free space .

Diameter of the disk is

Solution:

Diameter of the disk .