Question

1. Why is it important to use very small objects such as the polystyrene spheres in order to perform the lab?
   
2. What is it that causes the polystyrene spheres to become electrically charged as they leave the atomiser?
   
3. Is it theoretically possible for an object to have a charge of 4.00 x 10-19 C? Explain why or why not.
   
4. Suppose the separation between charged plates is 4.00 mm, the voltage of the plates is 200.0 V, and that the charge on the spheres is 6.2 x 10^-18 C. What must the mass of the sphere be if the force of gravity balances the electrical force?
   
5. Suppose that a charged polystyrene sphere acquires a negative charge and moves into the region between two plates that are horizontal relative to each other. Suppose the top plate is positively charged. The sphere is observed to fall. Which is greater, the force of gravity or the electrical force? Explain why you answer this way.

Answer 1

Very small objects are used because it is easier to transfer the charge through contact of surfaces in case of very small objects like polystyrene spheres.

As it leaves the atomiser, the sphere gains electrons and hence becomes electrically charged because of the excess of electrons.

Charge can only be transferred in multiples of 1.6 x 10^-19. Since 4 x 10^-19 is not a multiple of 1.6 x 10^-19, hence object can not have charge as 4 x 10^-19 C.