If the energy of a photon with a frequency of $2 \times 10^{12} \ Hz$ is $E$,then the energy of a photon with a frequency of $4 \times 10^{12} \ Hz$ will be ....

Give reasons for the failure of the Bohr Model.

What is the work function of the metal if the light of wavelength $4000 \, \mathring{A}$ generates photoelectrons of velocity $6 \times 10^5 \, ms^{-1}$ from it? ............. $eV$ (Mass of electron $= 9 \times 10^{-31} \, kg$; Velocity of light $= 3 \times 10^8 \, ms^{-1}$; Planck's constant $= 6.626 \times 10^{-34} \, Js$; Charge of electron $= 1.6 \times 10^{-19} \, C \, eV^{-1}$)

The maximum energy is present in any electron at

If the energy of the electron in a hydrogen atom in some excited state is $-3.4 \ eV,$ then what will be its angular momentum?

Match the spectral lines given in List-$I$ with their corresponding lower energy transitions given in List-$II$.

List-$I$	List-$II$
$(1)$ Lyman	$(A)$ $n = 5 \to n = 4$
$(2)$ Paschen	$(B)$ $n = 3 \to n = 2$
$(3)$ Brackett	$(C)$ $n = 6 \to n = 5$
$(4)$ Balmer	$(D)$ $n = 4 \to n = 3$
	$(E)$ $n = 7 \to n = 6$