Answers

2014-04-22T16:39:33+05:30
Current(I)= 0.2 A
Time(t) = 30 min = 30 * 60 = 1800 Sec.
I = Charge / t
     0.2 = Charge / 1800
       Charge(Q) = 0.2 * 1800 = 360 C
 I = no of electrons(n) * charge on electrons / t
          0.2 = n * 360 / 1800
            0.2 * 1800 / 360 = n
               n = 1

0
2014-04-22T23:13:40+05:30
We know that,
current(I)=charge(q)/time(t)
0.2=q/(30*60)
q=0.2*30*60
q=360 C
but,
1 C=6.2415*(10^18)
then
360 C=360*6.2415*(10^18)=n 
n=2246.94*10^18=224694*10^16
therefore,224694*10^16 electrons flow in the same time interval given.
hope this may be correct......!
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