Question

why TV screen becomes dusty soon

Answer 1

on screen a lil bit static type of electricity is produced so the dust particles hovering around the screen gets sticked to it and settles u would also have notice that when the TV is off and u put the arm on TV ur hairs feels a sensation .. this proves that the TV is charged even when there is no electricity

Answer 2

when TV is statted the static electricity of the screen attract the particles