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.

Sketch a graph between frequency of incident radiations and stopping potential for a given photosensitive material. What information can be obtained from the value of the intercept of potential axis? A source of light of frequency of greater than the threshold freuency is placed at a distance of 1 m from the cathode of a photocell? the distnace of hte light sources from the cathode is reduced explain giving reasons, what change will you observe in the Stopping potential.

Electromagnetic waves are those waves in which these are sinusoidal variation of electric and magnetic fields at right angle to each other as well as right angle ot the direction of propagation. The ratio of electric vector and magnetic vector gives the velocity of light and vecExxvecB gives the direction of propagation of electromagnetic wave. The electric field intensity produced by the radiations coming from 100 W bulb at a 3 m distance of E. The electric field intensity produced by the radiations coming from the 50 W bulb at the same distance is

Calculate the electric field and magnetic field produced by the rediation coming from a 100 W bulb at a distance of 3 m. Assume that the efficiency of the bulb is 2.5 % and it is a point source.

There are two sources of light, each emitting with a power of 100 W. One emits X-rays of wavelength 1nm and the other visible light of 500 nm. Find the ratio of number of photons of X-rays to the photons of visible light of the given wavelength?

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)

Light of intensity 10^-5 Wm^-2 falls on a sodium photocell of surface area 2 cm^2 . Assuming that the top 5 layers of sodium absorb the incident energy, estimate the time required for photoelectric emission on the wave picture of radiation. The work function for the metal is given to be about 2 eV. what is the implication of your answer?

Consider a 20 W bulb emitting light of wavelength 5000 oversetcircA and shining on a metal surface kept at a distance 2m . Assume that the metal surface work function of 2eV and that each atom on the metal surface can be treated as a cirular disc of radius 1.5 A. How much time would be required by the atomic disc to receive enrgy equal to work function.

STATEMENT-1: Emitted radiation will fall in visible trange when an electron jump from n=4ton=2 H-atom. STATEMENT-2: Balmer series radiations belong to visible for hydrogen atom only.

A point source S emitting light of wavelength 600 nm is placed at a very small height h above a flat reflecting surface AB [Fig.6.07].The intensity of the reflected light is 36% of the incident intensity.Interfrerence fringes are observed on a screen placed parallel to the reflecting surface at a very large distance D from it. What is the shape of the interference fringes on the screen?