The threshold wavelength for the photoelectric effect on sodium is $5000\;\mathring{A}$. Its work function is:

The work functions of Aluminium and Gold are $4.1\,eV$ and $5.1\,eV$ respectively. The ratio of the slope of the stopping potential versus frequency plot for Gold to that of Aluminium is $.......$

$A$ photon of energy $5.5 \ eV$ strikes a surface that emits photoelectrons with a maximum kinetic energy of $4.0 \ eV$. The stopping potential for these electrons is ............ $V$.

The work functions of metals $A, B$,and $C$ are $1.92 \ eV, 2.0 \ eV$,and $5 \ eV$ respectively. According to Einstein's photoelectric equation,which metal$(s)$ will emit photoelectrons when illuminated by light of wavelength $4100 \ \mathring{A}$?

In an experiment aimed to disprove Einstein's photoelectric equation,how did Millikan prove it?

Initially,a photon of wavelength $\lambda_1$ falls on a photocathode and emits an electron of maximum energy $E_1$. If the wavelength of the incident photon is changed to $\lambda_2$,the maximum energy of the electron emitted becomes $E_2$. Then the value of $hc$ ($h=$ Planck's constant,$c=$ velocity of light) is