Question

The potential difference applied to an X-ray tube is $16kV$ and the current through it is $2.4mA$, then find the number of electrons striking the target per minute.

• A. $9\times {10}^{16}$
• B. $9\times {10}^{17}$
• C. $9\times {10}^{15}$
• D. $9\times {10}^{18}$

Answer 1

The correct option is B $9\times {10}^{17}$

Current$=I=2.4mA=2.4\times {10}^{-3}A$

$t=1min=60s$

$q=It=2.4\times {10}^{-3}\times 60=0.144C$

$q=Ne$ where $N=$ number of electrons

$N=\frac{q}{e}=\frac{0.144}{1.6\times {10}^{-19}}$

$⟹N=9\times {10}^{17}$

Answer-(B)