In An Accelerator Experiment On High-energy Collisions Of The Electrons With Positrons, A Certain Event Is Interpreted As The Annihilation Of An Electron-positron Pair Of Total Energy 10.2 BeV Into Two -rays Of Equal Energy. Find The Wavelength Associated With Each -ray. 

X-rays of wavelength  are incident normally on a crystal and the second order reflection on diffraction from the crystal observed at an angle of 45^o. The lattice constant of the crystal is 

The frequency of  line of a source of atomic number Z is proportional to

A direct X-ray photograph of the intestines is not generally taken by the radiologists because :

X-rays which can penetrate through longer distance in substances are called.

The target in an X-rays tube should be a:

The maximum frequency of the X-rays produced in an X-ray tube

Which one of the following parameters of the emitted X-rays increases when the potential difference between the electrodes of an X-ray tube is increased?  

Calculate the energy of a photon, in electron-volt (eV) and in watt-hour (W h), of wavelength 6600 Å. 

An X-rays tube produces a continuous spectrum of radiation with its short wavelength end at 0.45 Å. What is the maximum energy of a photon in the radiation? What is the order of accelerating voltage (for electrons) required in such a tube? 

Energy from Sun is received on earth at the rate of . If average wavelength of solar light is taken as 550 nm, then how many photons are received on earth per meter² per second?