Which of the following particles has a mass similar to that of an electron?

The value of Planck's constant is

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

If the energy of a photon is $10\,eV$,then its momentum is

If $5\%$ of the energy supplied to a bulb is irradiated as visible light,how many quanta are emitted per second by a $100 \, W$ lamp? Assume the wavelength of visible light is $5.6 \times 10^{-5} \, cm$.

The momentum of a photon is $3.3 \times 10^{-29} \ kg \ m/s$. Its frequency will be