The correct option is B 5×10−3 ms−1
Drift velocity of an electron is given by vd=ineA
Given:
No. of electrons per m3, n=3×1023,
current i=24 mA and cross-sectional area, A=1 cm2 and electron charge e=1.6×10−19C.
On substituting the values, we get vd=24×10−33×1023×1.6×10−19×1×10−4 = 5×10−3 ms−1.