KCET2012PhysicsCurrent Electricity
A current of 2 ~A is passing through a metal wire of cross-sectional area 2 10⁻⁶ ~m ² . If the number density of free electrons in the wire is 5 10²⁶ ~m ⁻³ , the drift speed of electrons is (Given, e =1.6 10⁻¹⁹ C )
Options
- A1 32 ~ms ⁻¹
- B1 16 ~ms ⁻¹
- C1 40 ~ms ⁻¹
- D1 80 ~ms ⁻¹
Correct answer
D. 1 80 ~ms ⁻¹
Step-by-step solution
Drift velocity of electrons aligned v_ d &= I n e A &= 2 5 10²⁶ 1.6 10⁻¹⁹ 2 10⁻⁶ aligned or v _ d = 1 80 ~ms ⁻¹