Calculation of Charge in a Liquid Drop

Introduction
In order to calculate the charge in a liquid drop, it is important to have a basic understanding of electric charges and fields.

Electric Charges
Electric charges are fundamental properties of matter. There are two types of electric charges: positive and negative. Like charges repel each other while unlike charges attract each other. The SI unit of electric charge is coulomb (C).

Electric Field
An electric field is a region around a charged object where a force is exerted on other charged objects. The strength of an electric field is measured in volts per meter (V/m).

Calculation of Charge in a Liquid Drop
To calculate the charge in a liquid drop, we need to know the number of excess electrons present in the drop. Once we know the number of excess electrons, we can calculate the charge using the following formula:

Charge = Number of excess electrons x Charge on one electron

The charge on one electron is -1.602 x 10^-19 C.

For example, if a liquid drop has 20 excess electrons, the charge in the drop can be calculated as follows:

Charge = 20 x (-1.602 x 10^-19 C)

Charge = -3.204 x 10^-18 C

Therefore, the charge in the liquid drop is -3.204 x 10^-18 C.

Conclusion
In conclusion, the charge in a liquid drop can be calculated by multiplying the number of excess electrons by the charge on one electron. It is important to have a basic understanding of electric charges and fields in order to perform this calculation.

The initial charge of protons and electrons balance each other therefore initial charge of drop is 0
but when 20 extra electrons are added it aquires a negative charge of following value
charge of 1 e =1.6*10^-19 C
therefore charge due to 20 e = 20 * 1.6*10^-19 C
= 3.2*10^-18 C