The work functions for metals A, B and C are respectively 1.92 eV, 2.0 eV and 5 eV. According to Einsteins equation, the metals which will emit photoelectrons for a radiation of wavelength 4100 Å is/are

(a) None

(b) A only

(c) A and B only

(d) All three metals

So, only metals having work function less than 3eV can emit photoelectrons for the incident radiation of wavelength 4100 Å.

Dear Student,
Please find below the solution to your problem.

Energy of electron with an associated wavelength of 4100A∘ is:
⇒ hc/λ ​ =4.845×10^−19J
=3.024eV
This incident electron would emit photon from metals whose work potential is less than its energy.
Thus, it would emit photons from metals A and B

Thanks and Regards