Two sources A and B have same power . The wavelength of radiation of A is `lambda_a` and that of B is `lambda_b`.The number of photons emitted per second by A and B are `n_a` and `n_b` respectively, then

Two bulbs A and B are emitting monochromatic light of wavelength such that A can just ionise H atom and B can just ionise He^(+) ions. If the power of A and B are 30 W and 40 W respectively , the ratio of number of photons emitted per second by bulb A to bulb B is :

A laser beam of output power 'P' consists only of wavelength lambda . If Planck's constant is h and the speed of light is c , then the number of photons emitted per second is

According to Planck's quantum theory of light, every source of radiation emits photons (i.e., packets of energy ) which travel in all directions with the same speed (i.e., speed of light). Each photon is of energy E=hv=hc//lambda , where h is Planck's constant, v is the frequency and lambda is wavelength of radiation emitted. The photons emitted from different sources of radiation are different. Read the above passage and answer the following questions: (i) on what factors does the number of photons emitted per second from a source of radiations depends? (ii) Why are the high energy photons not vissible to eye? (iii) Which basic values do you learn from this study?

Let n_r and n_b be respectively the number of photons emitted by a red bulb and a blue blub of equal power in a given time.

Let n_r and n_b be respectively the number of photons emitted by a red bulb and a blue blub of equal power in a given time.

At t= 0 ,a sample of radionuclide A has the same decay rate as a sample of radionuclide B has at t = 60 min. The disintegration constants of A and B are lambda_(A) and lambda_(B) respectively, with lambda_(A) lt lambda_(B) .

Three ascending energy states of an atom are A,B,C. The wavelengths of emitted radiations due to transition from C to B and from B to A are lambda_1 and lambda_2 respectively. What will be the wavelength of emitted radiation due to transition from C to A ?

The energies of energy levels A, B and C for a given atom are in the sequence E_(A)ltE_(B)ltE_(C) . If the radiations of wavelength lambda_(1), lambda_(2) and lambda_(3) are emitted due to the atomic transitions C to B, B to A and C to A respectively then which of the following relations is correct :-