Calculate n(T)/n (1000 K) for tungsten emitter at T = 300 K, 2000 K and 3000 K where n(T) represents the number of thermions emitted per second by the surface at temperature T. Work function of tungsten is 4.52 eV.

According to Richardson-Dushman Equation thermionic current i is


where, n is the thermions emitted, S is the surface area, T is the absolute temperature, k is the Boltzmann constant, A is the constant depend on nature of metal and ϕ is the work function.


Case 1


T=300 K


Now,


Case 2


T=2000 K


Now,


Case 3


T=3000 K


Now,


1