KVPY SX SB Exam 2013 Question Paper

Photons of energy 7 eV are incident on two metals A and B with work functions 6 eV and 3 eV respectively. The minimum de Broglie wavelengths of the emitted photoelectrons with maximum energies are ${\mathit{\lambda }}_{\mathit{A}}$ and ${\mathit{\lambda }}_{\mathit{B}}$, respectively where $\frac{{\mathit{\lambda }}_{\mathrm{A}}}{{\mathit{\lambda }}_{\mathit{B}}}$ nearly