Question

The potential difference applied to a 3.2 mA X -ray tube is 5 kV. The number of the electrons striking the target per second is .

• A. $4.5\times {10}^{17}$
• B. ${10}^{18}$
• C. $5\times {10}^{16}$
• D. $2\times {10}^{16}$

Answer 1

The correct option is D $2\times {10}^{16}$

Let '$n$' be the number of electrons hitting the target. Let '$t$' be the total time the X-ray tube was in working condition.
We know that
$I=\frac{Q}{t}$ and $Q=\mathrm{ne}$

Therefore:
$\frac{n}{t}=\frac{\text{I}}{|\text{e}|}=\frac{3.2\times {10}^{-3}}{1.6\times {10}^{-19}}$
$=2\times {10}^{16}$ electrons