Correct Answer - Option 3 : 5.4 × 10
-19C
CONCEPT:
Electric charge:
- It is an intrinsic property of the elementary particles of matter which gives rise to electric force between various objects.
- It is a scalar quantity.
-
SI unit of electric charge is coulomb (C).
Quantisation of charge:
- The experimental fact that electric charges occur in discrete amounts instead of continuous amounts is called quantization of charge.
- All free charges are integral multiples of a basic unit of charge denoted by 'e'.
- Thus, the possible charge on a body is given by
⇒ q = ne
Where n is an integer e = 1.6 × 10-19C
CALCULATION:
\(n=\frac{q}{e}\)
Option 1:
q = 3.2 × 10-19 C
\(n=\frac{3.2\times 10^{-19}}{1.6\times 10^{-19}}=2\), n is an integer
Option 2:
q = 6.4 × 10-19C
\(n=\frac{6.4\times 10^{-19}}{1.6\times 10^{-19}}=4\) , n is an integer
Option 3:
q = 5.4 × 10-19C
\(n=\frac{5.4\times 10^{-19}}{1.6\times 10^{-19}}=3.375\) , n is not an integer
Option 4:
q = 4.8 × 10-19C
\(n=\frac{4.8\times 10^{-19}}{1.6\times 10^{-19}}=3\), n is an integer
- Therefore, the charge is not quantized, which means 5.4 × 10-19C cannot exist in nature.
-
Hence option 3 is correct
