Question

The work function for metals A, B and C are respectively 1.92 eV, 2.0 eV and 5 eV. According to Einstein’s equation, the metals which will emit photo electrons for a radiation of wavelength $4100\stackrel{\circ }{A}$ is/are

• A. None of these
• B. A only
• C. A and B only
• D. All the three metals

Answer 1

The correct option is C

A and B only

Energy of incident radiations (in eV) $=\frac{12375}{4100}=3.01eV$
Work function of metal A and B are less then 3.01eV, so A and B will emit photo electrons.