A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross section of the filament in 16 seconds would be where, e = 1.6 × 10 ^{ –19 } C
(a) 10 ^{ 20 }
(b) 10 ^{ 16 }
(c) 10 ^{ 18 }
(d) 10 ^{ 23 }
Answer:
Given,
- I = 1 A
- t = 16 seconds
- e = 1.6 × 10 ^{ -19 } C
We know that,
I = Q / t —------(i)
Where,
- Q is the electric charge
- t is time
We know that,
Q = n*e —---------(ii)
Where,
- n is the number of electrons.
- e is the charge of one electron.
Substituting (ii) in (i),
I = n*e / t
1 = n * 1.6 × 10 ^{ -19 } / 16
n = 1 * 16 / 1.6 × 10 ^{ -19 }
n = 10 * 10 ^{ 19 }
Therefore, n = 10 ^{ 20 }
So, the correct answer is (a).