1.
A and B are two metals with threshold frequencies 1.8×10141.8 \times 10^{14} Hz and 2.2×10142.2 \times 10^{14} Hz. Two identical photons of energy 0.8250.825 eV each are incident on them. Then photoelectrons are emitted by (Take h=6.6×1034h = 6.6 \times 10^{-34} J-s)