Dear Student,
Charge on one mole of protons
= 1.6x10^-19 x 6.023 x 10^23 = 96500 coulomb(1 Faraday)
We know that one proton has q charge then charge on one alpha particle will be 2q
so charge of one mole alpha particle enclosed in the box , Qin = 2 x 96500 = 193000 coulombs (2 Faraday)
Now,
Number of electric field emanating from the closed box ,
= 96500/8.8 * 10-12
=1.0966 * 10-8 N m2 C−1
Regards