If light waves pass through a $Nicol$ prism,then all the oscillations occur only in one plane. Such a beam of light is called:

If the energies of two photons are in the ratio of $3:2$,their wavelengths will be in the ratio of

The number of the following statements which is/are incorrect is:
$A$. Line emission spectra are used to study the electronic structure.
$B$. The emission spectra of atoms in the gas phase show a continuous spread of wavelength from red to violet.
$C$. An absorption spectrum is like the photographic negative of an emission spectrum.
$D$. The element helium was discovered in the sun by spectroscopic method.

Explain the production,characteristics,and uses of $X$-rays.

Assuming that the incident radiation is capable of ejecting photoelectrons from all the given metals,the lowest kinetic energy of the ejected photoelectron is observed with which of the given metals?

Calculate the wave number and frequency of orange radiation having wavelength $6300 \ \mathring{A}$.