The electron beam inside a television picture tube is 0.300mm in diameter and carries a current of 50.0 ?A. This electron beam impinges on the inside of the picture tube screen.
A) How many electrons strike the screen each second? (electons)
B) What is the current density in the electron beam? (A/m^2)
C) The electrons move with a velocity of 3.70 ×107m/s. What eectric field strength is needed to accelerate electrons from rest to this velocity in a distance of 5.00mm ? (N/C)
D) Each electron transfers its kinetic energy to the picture tube screen upon impact. What is the power delivered to the screen by the electron beam? (W)