Exams › NEET › Physics

Eight identical small drops, each of radius $r$ and carrying charge $q$, coalesce to form one large drop. What is the ratio of the electric potential of the big drop to that of one small drop?

1. 8:1
2. 4:1
3. 2:1
4. 1:8

Correct answer: 4:1

Solution

When eight identical drops merge, the total charge becomes $8q$ and the radius becomes $2r$ because volume adds. Since the potential of a charged sphere is $V=kQ/R$, the new potential is four times the original.

Related NEET Physics questions

• A capacitor is fully charged by a battery, and then the battery is disconnected. When a dielectric slab is inserted between the capacitor plates, what is the effect?
• In a charged capacitor, where is the energy stored?
• A capacitor of capacitance $C$ is charged to a potential $V$. The energy stored in it is:
• A capacitor of capacitance $50\,\mu\text{F}$ is charged to $10\,\text{V}$. What is the energy stored in it?
• A parallel-plate capacitor has air between its plates. When the air is replaced by a dielectric material of dielectric constant $K$, the capacitance:
• In a parallel-plate capacitor, one plate has a smaller area than the other. How does the charge on the smaller plate compare to the charge on the larger plate?

⚔️ Practice NEET Physics free + battle 1v1 →