Question

100 beta particles per minutes are passing through a straight tube of radius r .Find the net current through it

Answer 1

$\beta$ particle is same as electron.

so, charge on $\beta$- particle = charge on electron = 1.6 × 10^-19C

so, charge on 100 $\beta$ particles = 100 × 1.6 × 10^-19 C = 1.6 × 10^-17C

we know,

“current is the charge passing through per second a definite area.”

means, current = charge/time

= 1.6 × 10^-17C/1 minute

= 1.6 × 10^-17C/60s

= 0.027 × 10^-17 A

= 2.7 × 10^-19 A

hence, answer is 2.7 × 10^-19 A