Laser light of wavelength 660nm is used to weld a retina detachment. If the pulse has width 60 ms and power 0.5 KW the approximate number of photons in the pulse are?

Q. A Laser light of wavelength $660nm$ is used to weld Retina detachment. If a Laser pulse of width $60ms$ and power $0.5kW$ is used, the approximate number of photons in the pulse are:
[Take Planck's constant $h=6.62\times {10}^{-34}Js$]

Q. A laser used to weld detached retinas emits light with a wavelength of $652nm$ in pulses that are $20.0ms$ in duration. The average power during each pulse is $0.6W$. Then

Q. A laser used to weld detached retains emits light with a wavelength $652$ nm in pulses that are of $20ms$ duration. The average power during each pulse is $0.6W$. The energy in each pulse and in a single photon are :

Q. The approximate number of photons in a femtosecond $\left({10}^{-15}s\right)$ pulse of 600 nanometers wavelenghth light from a 10-kilowatt peak-power dye laser is

Q. A ruby laser produces radiations of wavelengths, 662.6 nm in pulse duration are 10${}^{-6}$s. If the laser produces 0.39 J of energy per pulse, how many photons are produced in each pulse?