(a) How manyelectrons strike the screen each second? ______ electrons (b) What i

Question

(a) How manyelectrons strike the screen each second?
   ______ electrons
(b) What is thecurrent density in the electron beam?


   ______ N/C (d) Eachelectron transfers its kinetic energy to the picture tube screenupon impact. What is the power delivered to thescreen by the electron beam?
   _______W

Explanation / Answer

(a) n / t = i / e = 48.0 x 10-6 / 1.6 x10-19                     = 30 x 1013 electrons /second (b) J = i / A = i / r2 = 48.0 x10-6 / 3.14 * (0.5 x 10-3)2= 61.14 A / m2 (c) acceleration of the electrons                  v2 = 2as           ==> a = v2 / 2s                      = 12.25 x 1014 / 2 * 4.30 x 10-3 = 1.424 x1011 m/s2 We know that      F = eq ma = Eq    ==> E = ma / q            = 9.1x 10-31 * 1.424 x 1011 / 1.6 x10-19                = 0.8101N/C (d) P = (n/t) * KE = 30 x 1013 *0.5 * 9.1 x 10-31 * 12.25 x 1014 =0.1672 W

Related Questions

Navigate

• Browse (All)
• Browse #
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.