The ionization potential of hydrogen atom is $13.6 \ eV$. The energy required to remove an electron from the $n = 2$ state of hydrogen atom is : ............ $eV$

According to the Bohr model for the hydrogen atom,the radius of stationary orbits is proportional to which of the following?

What is the maximum wavelength in the Lyman series of $He^{+}$ ion?

The wavelength of $H_{\alpha}$ line of Balmer series is $X \ \mathring{A}$. What is the wavelength of $H_{\beta}$ line of Balmer series?

The correct representation of the wavelength-intensity relationship of an ideal black body radiation at two different temperatures $T_{1}$ and $T_{2}$ (where $T_{2} > T_{1}$) is:

$A$ bulb emits light of wavelength $4500 \ \mathring{A}$. The bulb is rated at $150 \ W$ and $8 \ \%$ of the energy is emitted as light. What is the number of photons emitted by the bulb in $1 \ s$?