Which statement best describes semi-conductors: A) Lack free electrons that can move to other atoms
B) Electrons within their atoms are paired
C) Most electrons within atoms are paired
D) Electricity can flow through it under special conditions

Suppose a diode consists of a cylindrical cathode with a radius of 6.200×10^−2 cm , mounted coaxially within a cylindrical anode with a radius of 0.5580 cm . the potential difference between the anode and cathode is 260 v . an electron leaves the surface of the cathode with zero initial speed (v initial=0). find its speed vfinal when it strikes the anode.