A beam of ligh incident on a surface has photons each of energy 1 mJ and intensity `25w//cm^(2)`. Find number of photons incident per second if surface area of `25cm^(2)`
A beam of light having wavelength lambda and intensity 1 falls normally on an area A of a clean surface then find out the number of photon incident on the surface.
A parellel beam of monochromatic light of wavelength 500 nm is incident normally on a perfectly absorbing surface. The power through any cross section of the beam is 10 W. Find (a) the number of photons absorbed per second by the surface and (b) the force exerted by the light beam on the surface.
A laser beam of power 20W incident normally on a surface. if 25% light is absorbed and rest reflected find magnitude of force experienced by the surface.
A monochromatic beam of light (lamda=4900A) incident normally upon a surface produces a pressure of 5xx10^(-7)Nm^(-2) on it. Assume that 25% of the light incident in reflected and the rest absorbed. Find the number of photons falling per second on a unit area of thin surface
Light of wavelength 5000 Å and intensity of 3.96 xx 10^(-3) watt//cm^(2) is incident on the surface of photo metal . If 1% of the incident photons only emit photo electrons , then the number of electrons emitted per unit area per second from the surface will be
Ultraviolet light of wavelength 300nn and intensity 1.0Wm^-2 falls on the surface of a photosensitive material. If one per cent of the incident photons produce photoelectrons, then the number of photoelectrons emitted per second from an area of 1.0 cm^2 of the surface is nearly
Light of wavelength 3000 Å falls on a sensitive surface. If the surface has received 10^-7 J of energy, then number of photons just falling on the surface area
(a) Calculate the momentum of a photon of light of wavelength 500 nm. (b) Find the number of photons emitted per second by a 25 W sourse of monochromatic light of wave length 600 nm. (c) How many photons per second does a one watt bulb emit if its efficiency is 10% and the wavelength of light emitted is 500 nm? (d) Monochromatic light of wavelength 300 nm is incident normally on a surface of area 4 cm^(2) . If the intensity of light is 150 m W//m^(2) , determine the rate at which photons strike the surface.
