Question
Physics Question on Current electricity
A current of 5A is passing through a metallic wire of cross-sectional area 4×10−6m2 If the density of the charge carriers in the wire is 5 ? 1026m−3, the drift speed of the electrons will be [e = 1.602 ? 10−19C]
A
1.56×10−2ms−1
B
1.98?10−2ms−1
C
2.42?10−2ms−1
D
2.84?10−2ms−1
Answer
1.56×10−2ms−1
Explanation
Solution
In a metal, conduction current is due to electrons given by
I=nAev
⇒ drift velocity, V=nAeI
⇒v=5?1026?4?10−6?1.602?10−195
=4?1.602?1011
=6.40810−1=1.56?10−2m/s