Question

10^12 alpha particles fall per second on a neutral sphere; calculate the time in which the sphere gets charged by 2micro coulumb. ​

Answer 1

Given:

10^12 alpha particles fall per second on a neutral sphere.

To find:

Time in which the spear gets charged to 2 micro-C.

Calculation:

Alpha particles are actually double positively charged Helium ions.

$\boxed{ \sf{ \alpha \: \: particles = {He}^{ + 2} }}$

So , each Alpha particle has positive charge equivalent to magnitude of two electron charge.

Let time taken be t ;

$\rm{ \therefore \: t = \dfrac{total \: charge}{charge \: per \: second} }$

$\rm{ = > \: t = \dfrac{2 \times {10}^{ - 6} }{ {10}^{12} \times( 2 \times 1.6 \times {10}^{ - 19}) } }$

$\rm{ = > \: t = 6.25 \times {10}^{ - 18} \times {10}^{6} }$

$\rm{ = > \: t = 6.25 \times {10}^{ - 12} \: sec }$

So, final answer is :

$\boxed{ \blue{ \sf{ \: t = 6.25 \times {10}^{ - 12} \: sec }}}$