Question

If an electron revolves in the path of a circle of radius $0.5\times 10$${}^{-10}$$m$ at a frequency of $5\times 10$${}^{15}$ cycles/s, the electric current in the circle is (charge of an electron $=$ 1.6 x 10${}^{-19}$)

• A. $0.4mA$
• B. $0.8mA$
• C. $1.2mA$
• D. $1.6mA$

Answer 1

The correct option is B $0.8mA$

$I=\frac{\Delta Q}{t}$
$=1.6\times {10}^{-19}\times 5\times {10}^{15}$
$=8\times {10}^{-4}$
$I=0.8mA$