CGPET 2019 Solved Paper

Given, the current flowing in a copper voltmeter, I=1.6A
As we know that,
Charge, Q= Total number of ions × Charge on electron (e)
Q=n×e .......(i)
Charge Q=

Current

Time

Q=

I

t

From Eq. (i), we get
n×e=

I

t

(∵t=1min given )
n×1.6×10−19=1.6(∵e=1.6×10−19C)
Now, the number of Cu++ ions deposited at the cathode per minute is n=

1.6

1.6×10−19

n=1×1019