Two metals X and Y have work functions 2eV and 5eV respectively. Which metal will emit electrons when it is irradiated with light of wavelenth 400 nm and why?

Two metals X and Y have work functions 2eV and 5eV respectively. Which metal will emit electrons, when irradiated with light of wavelength 400m, and why?

Two metal A and B have work functions, 2eV and 5eV respectively. Which metal has lower threshold wavelength?

Two metals A and B have work functions 4eV and 10eV respectively. Which metal has higher threshold wavelength?

A metal has work function 5eV. Will this metal emit electrons, when light of wavelength 400 nm falls on it?

Three photo diodes D_1 , D_2 and D_3 are made of semiconductors having band gaps of 2.5 eV, 2eV and 3eV, respectively. Which ones will be able to detect light of wavelength 6000 oversetcircA ?