Question

Which of the following equations represent photoelectric effect?

• A. $h\gamma =h{\gamma }_0+\frac{1}{2}m{v}^2$
• B. $h\gamma =W+h{\gamma }_0$
• C. $h{\gamma }_0=W-h{\gamma }^2$
• D. $h{\gamma }_0=W+h\gamma$

Answer 1

The correct option is A $h\gamma =h{\gamma }_0+\frac{1}{2}m{v}^2$

This equation is given by Einstein. It says that some energy of incident radiation is used to knock out the electrons from the metal surface $h{\nu }_0$ where ${\nu }_0$ is the threshold frequency. And the remaining energy is used as K.E. of the emitted photoelectron.

$h{\nu }_0$ is work function of the material defined as min. energy required to remove the electron from the metal surface.