99 Percentile Qs Bank for JEE MainPhysicsCurrent Electricity
Every atom makes one free electron in copper. If 1 . 1 A Current is flowing in the wire of copper having 1 mm diameter, then the drift velocity (approx.) will be (density of copper = 9 × 10 3 k g m - 3 and atomic weight of copper = 63 )
Options
- A0.1 m m s - 1
- B0.2 m m s - 1
- C0.3 m m s - 1
- D0.2 m m s - 1
Correct answer
A. 0.1 m m s - 1
Step-by-step solution
v d = i n Ae ; where n = N A ρ M = 6.023 × 10 26 × 9 × 10 3 63 = 0.860 × 1 0 2 9 = 8.6 × 10 28 and A = π D 2 4 = 22 7 × 10 - 3 2 4 m 2 ; = 11 14 × 10 - 6 m 2 v d = 1.1 8.6 × 10 28 × 11 14 × 10 - 6 × 1.6 × 10 - 19 = 1 9.6 × 1 0 + 3 = 1 0 0 × 1 0 - 4 9 6 = 1.0 × 1 0 - 4 m s - 1 = 0.1 m m s - 1