Question

The current in a Crookes tube is$10nA$. How many electrons strike the face of the glass tube each second?

Short answer

Number of electrons$=625\times {10}^8$

Step-by-step solution

Given information:

We have given that

Current (I)$=10nA$

Time (T)$=1s$

Here we need to calculate the number of electrons striking the face of glass tube each second through the formula$\mathrm{I}=\frac{\mathrm{Q}}{\mathrm{T}}$where I is the current and Q is the total charge of all electrons flowing in the tube in the given time T.

Explanation:

Charge on electron (e)$=1.6\times {10}^{-19}C$

Now, let the number of electrons be$=N$

According to the formula: $\mathrm{I}=\frac{\mathrm{Q}}{\mathrm{T}}$

$\mathrm{I}=\frac{\mathrm{Ne}}{\mathrm{T}}$ $\left(Q=Ne\right)$

$10nA=\frac{N\left(1.6\times {10}^{-19}C\right)}{1s}$

$N=625\times {10}^8$