Question

Thermionic emission from a heated filament varies with its temperature T as

• A. $T^{- 1}$
• B. $T$
• C. $T^{2}$
• D. $T^{3/2}$

Answer 1

Answer: (C)

$T^{2}$

Answer 2

According to Richardson-Dushman equation, number of thermions emitted per sec per unit area $J = AT^{2}e^{- W_{0}/kT}$

⇒ $J \propto T^{2}$