Chapter 21.2, Problem 44SSC

To determine

To Explain:The way potential difference should be adjusted to bring the drop back into balance.

Explanation of Solution

Introduction:

Millikan’s oil drop experiment was used to determine the magnitude of electric charge. In this experiment, a charged oil droplet is suspended in an electric field. The electric force on the charge is balanced by its weight. The charge on the droplet depends on the electric field’s strength and its mass.

When the net charge on the droplet is changed and it begins to fall, it signifies the weight of the droplet is more than the electric force acting on it. As the electric field pushes the charge upwards and its strength depends on the potential difference between the plates, the later must be increased till the droplet stops falling down and balance is restored.

Conclusion:

The potential difference between the conducting plates must be increased to bring back the charged droplet to balance.