Correct Answer - Option 2 : About 200 years
Concept:
Electric charge: It is the transfer of electrons from one material to another. So negative charge means that there is an excess of electrons while a positive charge is a deficiency of electrons.
The quantization of charge means that the charge on an object is an integral multiple of the basic unit of charge( charge on one electron). It is given by
Q = n e
Where n = Some integer, e = Charge on an electron = 1.6 × 10-19C
Calculation:
Given:
N = 109 /s, Q = 1 C, 1yr ≈ 3 x 107 s
n = x × 109
Here x is the time in seconds
Using Q = n e
1 = x × 109 × 1.6 × 10-19
x = 0.625 × 1010 s
For time in years, we have to divide by 1yr ≈ 3 x 107 sec
x = \(\frac {0.625\ \times \ 10^{10}}{3\ \times \ 10^7}\)
x = 208.33 years
Closest answer is 200 years