MCQ
Which one is correct relation for thermionic emission
 
  • A
    $J=A T^{1 / 2} e^{-\emptyset / k T}$
  • $J = AT ^2 e ^{-\varnothing / kT }$
  • C
    $J=A T^{3 / 2} e^{-\emptyset / k T}$
  • D
    $J=A T^2 e^{-\emptyset / 2 k T}$

Answer

Correct option: B.
$J = AT ^2 e ^{-\varnothing / kT }$
(b) $J = AT ^2 e ^{-\varnothing / kT }$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

A sine wave is travelling in a medium. The minimum distance between the two particles, always having same speed, is:
An object is located in a fixed position in front of a screen. Sharp image is obtained on the screen for two positions of a thin lens separated by $10\, cm$. The size of the images in two situations are in the ratio $3 : 2$. What is the distance between the screen and the object?......$cm$
Rest mass energy of an electron is $0.51\  MeV.$ If this electron is moving with a velocity $0.8\ c$ (where $c$ is velocity of light in vacuum), then kinetic energy of the electron should be. ........... $MeV$
The equivalent capacitance between $A$ and $B$ in the figure is $1\,\mu F$. Then the value of capacitance $C$ is.....$\mu F$
The slopes of anode and mutual characteristics of a triode are $0.02 \ mA\ V^{-1}$ and 1 mA $V^{-1}$ respectively. What is the amplification factor of the valve
$Assertion\,(A):$ A charge $q$ is placed on a height $h / 4$ above the centre of a square of side b. The flux associated with the square is independent of side length.

$Reason\,(R):$ Gauss's law is independent of size of the Gaussian surface.

To obtain a $P-$type germanium semiconductor, it must be doped with
Zener diode acts as $a/an$ :
Which of the following phenomenon can explain quantum nature of light:
A capacitor $C$ is fully charged with voltage $V _{0}$ After disconnecting the voltage source, it is connected in parallel with another uncharged capacitor of capacitance $\frac{ C }{2} .$ The energy loss in the process after the charge is distributed between the two capacitors is$.........$$CV _{0}^{2}$