A negatively charged oil drop remains at rest, midway between two plates linked to a high voltage supply, as shown. Which alteration would not make the upward electrical force on the drop greater?
- Adecreasing the distance between the plates whilst keeping the drop equidistant from them
- Bincreasing the amount of negative charge on the drop
- Cincreasing the supply voltage
- Dmoving the drop closer to the positive plate