Identify the correct statements among the following.
(A) For two unlike equal charges, there is a neutral point on the middle point on the line joining the two charges.
(B) For two unlike unequal charges, the neutral point will be outside on the line joining the two charges.
(C) For two positive equal charges, the neutral point will be at the middle point of the line joining the two charges.
(D) For two negative charges placed along a line, there will not be any neutral point.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (B) and (C) only
A neutral point is where the resultant electric field is zero. The two fields there must be equal in size and opposite in direction.
(A) For two unlike equal charges, there is a neutral point on the middle point on the line joining the two charges. — Incorrect. Between unlike charges both fields point from the positive towards the negative charge, so they add, not cancel.
(B) For two unlike unequal charges, the neutral point will be outside on the line joining the two charges. — Correct. The fields are opposite only outside the charges, and equal only on the side of the smaller charge.
(C) For two positive equal charges, the neutral point will be at the middle point of the line joining the two charges. — Correct. At the midpoint the two fields are equal and point away from each charge, so they cancel.
(D) For two negative charges placed along a line, there will not be any neutral point. — Incorrect. Between two like charges the fields are opposite, so a neutral point lies between them.