If p is the momentum of the fastest electron ejected from a metal surface after the irradiation of light having wavelength $$\lambda $$, then for 1.5 p momentum of the photoelectron, the wavelength of the light should be: (Assume kinetic energy of ejected photoelectron to be very high in comparison to work function)

The quantum number of four electrons are given below :
n = 4, l = 2, m_l =–2, m_s = –1/2
n = 3, l = 2, m_l = 1, m_s = +1/2
n = 4, l = 1, m_l = 0, m_s = +1/2
n = 3, l = 1, m_l = 1, m_s = –1/2
The correct order of their increasing enegies will be :

If the de Broglie wavelength of the electron in n^th Bohr orbit in a hydrogenic atom is equal to 1.5 $$\pi $$a₀ (a₀ is Bohr radius), then the value of n/z is -

The upper stratosphere consisting of the ozone layer protects us from sun's radiation that falls in the wavelength region of -