Calculate the energies of the photons associated with the following radiation:
(i) violet light of 413 nm
(ii) X-rays of 0.1 nm
(iii) radio waves of 10 m.

A 150 W lamp emits light of mean wavelength of 5500 Å. If the efficiency is 12%, find out the number of photons emitted by the lamp in one second.

How many photons of frequency 10¹⁴ Hz will make up 19.86 J of energy?

When a 6000Å light falls on the cathode of a photo cell, photoemission takes place. If a potential of 0.8 V is required to stop emission of electron, then determine the
(i) frequency of the light
(ii) energy of the incident photon
(iii) work function of the cathode material
(iv) threshold frequency and
(v) net energy of the electron after it leaves the surface.

A 3310 Å photon liberates an electron from a material with energy 3 x10^-19 J while another 5000 Å photon ejects an electron with energy 0.972 x 10^-19 J from the same material. Determine the value of Planck’s constant and the threshold wavelength of the material.

UV light of wavelength 1800 Å is incident on a lithium surface whose threshold wavelength is 4965 Å. Determine the maximum energy of the electron emitted.

An electron is accelerated through a potential difference of 81V. What is the de Broglie wavelength associated with it? To which part of electromagnetic spectrum does this wavelength correspond?

The ratio between the de Broglie wavelength associated with proton, accelerated through a potential of 512 V and that of alpha particle accelerated through a potential of X volts is found to be one. Find the value of X.

Find the de Broglie wavelength associated with an alpha particle which is accelerated through a potential difference of 400 V. Given that the mass of the proton is 1.67 x 10^–27 kg.

Calculate the cut-off wavelength and cutoff frequency of x-rays from an x-ray tube of accelerating potential 20,000 V.