The ratio of the energy of a photon with $\lambda = 150\,nm$ to that with $\lambda = 300\,nm$ is

Monochromatic light of wavelength $667 \,\,nm$ is produced by a helium neon laser. The power emitted is $9 \,\,mW.$ The number of photons arriving per sec. on the average at a target irradiated by this beam is

Monochromatic light of frequency $6 \times 10^{14} \mathrm{~Hz}$ is produced by a laser. The power emitted is $2 \times 10^{-3} \mathrm{~W}$. How many photons per second on an average, are emitted by the source?

(Given $\mathrm{h}=6.63 \times 10^{-34} \mathrm{Js}$ )

Monochromatic light of frequency $6.0 \times 10^{14}\,\, Hz$ is produced by a laser. The power emitted is $2 \times 10^{-3}\,\, W.$ The number of photons emitted, on the average, by the source per second is

The incident photon involved in the photoelectric effect experiment.

By suitable example show that particle or wave nature depend on type of experiment.