Constants ? Part A Before the advent of solid-state electronics, vacuum tubes we
ID: 1730825 • Letter: C
Question
Constants ? Part A Before the advent of solid-state electronics, vacuum tubes were widely used in radios and other devices. A simple type of vacuum tube known as a diode consists essentially of two electrodes within a highly evacuated enclosure. One electrode, the cathode, is maintained at a Suppose a diode consists of a cylindrical cathode with a radius of 6.200x102 cm, mounted coaxially within a cylindrical anode with a radius of 0.5580 cm. The potential difference between the anode and cathode is 230 V.An electron leaves the surface of the cathode with zero initial speed (Vinitial 0). Find its speed vfinal when it strikes the anode. Express your answer numerically in meters per second. Figure 1 of 1 Vfinal m/s Submit Request Answer Provide Feedback Next>Explanation / Answer
We know that the initial energy of the electron = qV
where q is charge on electron and V is potential difference
Final energy of the electron = kinetic energy = (1/2)mv2
where m is mass of electron
v is speed of electron
Now, by energy conservation
qV = (1/2)mv2
v2 = 2qV/m
v2 = [(2*1.6*10-19*230) /(9.11*10-31)]
v = 8.99*106 m/s