Home › UP Board Class 12 › Physics › Electric Charges and Fields › The smallest charge that can exist freely in nat…
The smallest charge that can exist freely in nature is
A$+1\,\text{C}$
B$e = 1.6\times 10^{-19}\,\text{C}$
Cthe mass of an electron
Dzero
Answer & Solution
Correct answer: B. $e = 1.6\times 10^{-19}\,\text{C}$
1. NCERT §1.4 states the QUANTISATION of electric charge: $q = ne$ for some integer $n$.
2. The elementary charge is $e = 1.6\times 10^{-19}\,\text{C}$ — the magnitude of the charge on an electron (or a proton).
3. Free quarks would carry fractional charge, but they are confined inside hadrons and never observed in isolation. So $e$ is the smallest FREE charge.
4. Macroscopic charges always come as integer multiples of $e$.
5. Option A is a huge macroscopic charge. Option C is a MASS, not a charge. Option D contradicts the existence of charged objects.
_Source: NCERT Class 12 Physics Part 1, Ch 1 "Electric Charges and Fields", §1.4 (Quantisation of Charge) + §1.5, p. 4–5._
Related questions
A charged comb picks up small pieces of paper that carry no net charge, because the paper Compared with the tiny nucleus, the electrons around it form a cloud that is:Benjamin Franklin explained early observations by supposing that one type of charge stayedA test charge or a source charge moves, and as a result the force between them:If the two ends of a dipole can be pulled apart, induction can create charged objects withPlaced in a uniform field, such a dipole experiences a turning effect that changes its angTwo equal and opposite charges separated by a small distance form a dipole, characterised Where those lines are packed more densely, the field is: