If 5 % of the energy supplied to an incandescent light bulb is radiated as visible ligth,how many visible light photons are emitted y a 100 watt bulb?Assume the average wabelength of all visible photons to be `5,600 D`.Given,`h=6.625 xx 10^(-34) J s`.

Calculate the wavelength of a photon of energy 10^(10) eV (electron volt(. Given Planck.s constant h=6.625 xx 10^(-34) Js (Joule Second).

Calculate the number of photons in 6.62 J of radiation energy of frequency 10^(12) Hz. Given h=6.62 xx 10^(-34) Js.

About 5% of the power of a 100 W light bulb is converted to visible radiation. What is the average intensity of visible radiation at a distance of lm from the bulb? Assume that the radiation is emitted isotropically and neglect reflection.

About 5% of the power of a 100 W light bulb is converted to visible radiation. What is the average intensity of visible radiation at a distance of 10 m? Assume that the radiation is emitted isotropically and neglect reflection.

Infrared lamps are used in restaurants to keep the food warm. The infrared radiation is strongly absorbed by water, raising its temperature and that of the food. If the wavelength of infrared radiationis assumed to be 1500 nm, and the number of quanta of infrared radiation produced per second by an infrared lamp (that consumes enregy at the rate of 100 W and is 12% effcient only) is (xx10^(19) , then the value of x is : (Given: h= 6.665xx10^(-34)J-s)

In a photoelectric effect set up, a point source of light of power 3.2 xx10^(-3) W emits monoenergetic photons of energy 5eV.The source is located at a distance of a stationary metallic sphere of work function 3eV and radius 8xx10^(-3)m .The efficiency of photoelectron emission is one for every 10^(6) incident photons.Assume that the sphere is isolated and initially neutral and the photoelectrons are initially swept away after emission. Find the ratio of the wavelength of incident light to the de Broglie wavelength of the fastest phtotelectrons emitted.

Assume that 10^(-17) J of light energy is needed by the interior of the human eye to see an object . How many photons of green light (lambda = 495nm) are needed to generate this minimum energy . [h=6.6xx10^(-34) Js]