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

The wavelength of photon $A$ is $400 \ nm$. The frequency of photon $B$ is $10^{16} \ s^{-1}$. The wave number of photon $C$ is $10^{4} \ cm^{-1}$. The correct order of energy of these photons is:

Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength $8000 \ \mathring{A}$. What should be the maximum velocity of emitted electron when the same metal surface is exposed to radiation of wavelength $5000 \ \mathring{A}$? $\left( h = 6.6 \times 10^{-34} \ J \cdot s, \ m_e = 9.1 \times 10^{-31} \ kg, \ c = 3 \times 10^8 \ m/s \right)$

The hydrogen spectrum from an incandescent source of hydrogen is:

Which one of the following frequencies of radiation (in $Hz$) has a wavelength of $600 \ nm$?

The wavelength of a spectral line of caesium is $460 \ nm$. What is the frequency of the spectral line?