Question

Calculate the energy of photons having wavelength, $5\times {10}^{-7}m$ falls on a metal surface of work function, $3.4\times {10}^{-19}J$:

• A. $3.97\times {10}^{-19}J$
• B. $3.55\times {10}^{-19}J$
• C. $2.97\times {10}^{-19}J$
• D. $2.57\times {10}^{-19}J$

Answer 1

The correct option is A $3.97\times {10}^{-19}J$

Energy of pphotons,

$E=hv=\frac{hc}{\lambda }$

$=\frac{(6.626\times {10}^{-34}Js)\times (3\times {10}^{8}m{s}^{-1})}{5\times {10}^{-7}}$

$=3.975\times {10}^{-19}J$