Question

Like charges repel each other. This statement is:
(a). True always
(b). False always
(c). Either true or false
(d). Neither true or false

Answer 1

- Hint: There are two types of charges, one is the positive charge and the other one is the negative charge. Each charge produces an electric field of its own and depending on the charge, the direction of the field line is determined.

Complete step-by-step solution -
We know that there are two types of charges, one is the positive charges and the other one is the negative charge. Each charge however small it is produces an electric field. The electric field lines produced by a positive charge are always coming out of the charge while the electric field lines produced by a negative charge are always going into the charge. Also, the electric field at a point is the force experienced by a unit positive charge. So when the electric field is produced by a positive charge, the field will be going outward and this field will tend to repel the unit charge since it is positive.
The fact that the like charges repel or the unlike charges attract is an experimental fact. If we try to bring like-charged particles close to each other they always repel each other. Also if we rub a plastic rod with a silk cloth, the plastic rod gains a positive charge. If we have bits of paper laid on a table, the plastic attracts the pieces of paper. This is possible due to the polarization of charge in the paper, the negative charges in the paper get attracted toward the side of the rod which shows the attraction of unlike charges. The positive charges in the paper get repelled to the opposite side of the paper.
So, these kinds of experiments show that the like charges repel and unlike charges attract.

So the answer to the question is option (A)- True Always.

Note: Electron is a negative charge while the proton is an example of a positive charge. So electrons and a proton which are unlike charges attract each other and electron-electrons or a proton-proton combination which are like charges repel each other.
Since the mass of electron $$(9.1\times {10}^{-31}kg)$$ is smaller than the mass of the proton $(1.67\times {10}^{-27}kg)$, the electron moves the most distance when an electron and proton are attracted to each other.
Electric fields produced by positive or negative charges follow the inverse square law just like the gravitational field.