Current Electricity Charging Discharging Of Capacitors Question 694
Question: An electron beam has an aperture $ 1.0mm^{2}. $ A total of $ 6\times 10^{6} $ electrons go through any perpendicular cross section per second. Find the current density in the beam. (in $ A/m^{2} $ )
Options:
A) $ 9.1\times 10^{13} $
B) $ 9.6\times 10^{3} $
C) $ 6.6\times 10^{5} $
D) $ 8.6\times 10^{11} $
Show Answer
Answer:
Correct Answer: B
Solution:
[b] $ J=I/A=Q/tA={}^{ne}/{} _{tA} $
$ =9.6\times 10^{3}A/m^{2} $
BETA
