Q. The potential difference applied to an X-ray tube is 5 kV and the current through it is 3.2 mA. The number of electrons striking the target per second is (Take $e\ $=$1.6 \times 10^{- 19}$ C)
A) $1.6 \times 10^{6}$
B) $2 \times 10^{- 6}$
C) $4 \times 10^{16}$
D) $2 \times 10^{16}$
Explanation
(d) Current $\ \ \ \ \ \ \ \ \ i = \frac{ne}{t}$
$\Rightarrow \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \frac{n}{t} = \frac{i}{e} = \frac{3.2 \times 10^{- 3}}{1.6 \times 10^{- 19}} = 2 \times 10^{6}/s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.