14) Two point charges are kept separated by 4cm of air and 6cm of a dielectric of relative permitivity 4, Te equivalent dielectric separation between them so far theircoulombian interaction is conserved is?

16) charge on 500cc water due to protons will be?

Equivalent dielectric separation is given by:

500 cc = 500 ml = 500 gm

so, the number of moles of water = 500 / atomic weight = 500 / 18 = 27.78 moles.

thus, the number of molecules would be = number of moles X Avagadro's Number

or

the total number of molecules = 27.78 X 6.023 X 10²³ = 1.67 X 10²⁵ and each water molecule has 10 protons in it. thus total number of protons in 500 cc of water would be = total number of molecules X 10 = 1.67 X 10²⁶ protons

thus, the total protonic charge = number of protons X protonic charge or Q = ne or Q = 1.67 X 10²⁶ X 1.6 X 10^-19 C

Thus, the required answer is the total charge due to protons in 500cc of water Q = 2.67 X 10 ⁷ C