Question

. A cathode ray tube (CRT) is a device that produces a focused beam of electrons in a vacuum. The electrons strike a phosphor-coated glass screen at the end of the tube, which produces a bright spot of light. The position of the bright spot of light on the screen can be adjusted by deflecting the electrons with electrical fields, magnetic fields, or both. Although the CRT tube was once commonly found in televisions, computer displays, and oscilloscopes, newer appliances use a liquid crystal display (LCD) or plasma screen. You still may come across a CRT in your study of science. Consider a CRT with an electron beam average current of 25.00μA25.00μA . How many electrons strike the screen every minute?

Answer 1

Answer:

The value is $n= 9.375 *10^{15} \ electrons$

Explanation:

From the question we are told that

  The average current is  $I = 25.0 \mu A = 25.0 *10^{-6} \ A$

Generally the quantity of charge (electron )  is mathematically represented as

       $Q = ne$

Here e is the charge on a single electron with value $e = 1.60 *10^{-19} \ C$

   Generally current is mathematically represented as

     $I = \frac{Q}{t}$

=>   $I = \frac{ne}{t}$

Here t is time which is given as 1 minutes =  60  seconds

  and  n is the number of electrons

So

      $25.0 *10^{-6} = \frac{ n* 1.60 *10^{-19}}{60}$

=>    $60 * 25.0 *10^{-6} = n* 1.60 *10^{-19}$

=>    $n= \frac{60 * 25.0 *10^{-6} }{ 1.60 *10^{-19} }$

=>    $n= 9.375 *10^{15} \ electrons$