Questions in Dual Nature of Radiation and Matter

Select	Question
	Threshold wavelength for photoelectric effect on sodium is 5000 Å. Its work function is
	The cathode of a photoelectric cell is changed such that the work function changes from $W_1$ to $W_2$ ($W_2 > W_1$). If the current before and after change are $I_1$ and $I_2$, all other conditions remaining unchanged, then (assuming $h\nu > W_2$)
	A beam of light of wavelength $\lambda $ and with illumination L falls on a clean surface of sodium. If N photoelectrons are emitted each with kinetic energy E, then
	Which of the following statements is correct
	What is the stopping potential when the metal with work function 0.6 eV is illuminated with the light of 2 eV
	When yellow light is incident on a surface, no electrons are emitted while green light can emit. If red light is incident on the surface, then
	The photoelectric threshold wavelength of a certain metal is 3000Å. If the radiation of 2000Å is incident on the metal
	A photocell stops emission if it is maintained at 2V negative potential. The energy of most energetic photoelectron is
	The work functions for sodium and copper are $2eV$ and $4eV$. Which of them is suitable for a photocell with 4000 Å light
	For intensity I of a light of wavelength 5000Å the photoelectron saturation current is 0.40 $\mu \,A$ and stopping potential is 1.36 V, the work function of metal is