In the hydrogen spectrum,the various lines of the Lyman series lie in the $.......$ region.

$A$ hypothetical electromagnetic wave is shown below. The frequency of the wave is $x \times 10^{19} \ Hz$. $x =$ . . . . (nearest integer)

The photoelectric effect can be caused by which of the following?

Splitting of spectral lines when atoms are subjected to a strong electric field is called:

$a$,$b$,$c$,$d$ are electromagnetic radiations. Frequencies of $a$,$b$ are $3 \times 10^{15} \ Hz$,$2 \times 10^{14} \ Hz$,respectively,whereas wavelengths of $c$,$d$ are $400 \ nm$,$750 \ nm$,respectively. The increasing order of their energies is

Calculate the energy per mole of photons of electromagnetic radiation having a wavelength of $700 \ nm$. $\left[h = 6.626 \times 10^{-34} \ J \ s, c = 3 \times 10^8 \ m/s, N_A = 6.022 \times 10^{23} \ mol^{-1}\right]$