19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
The most probable radius (in pm) for finding the electron in He⁺ is
Bohr's theory is NOT applicable to:
According to Bohr's theory, the angular momentum of an electron in 5th orbit is
When electrons of a hydrogen atom return to the L shell (n=2) from higher energy shells, the series of lines formed is called
Which series in the hydrogen spectrum lies in the ultraviolet region?
In the hydrogen spectrum, the Balmer series lies in which region?
The ratio of the energy difference between the 1st and 2nd Bohr orbits to that between the 2nd and 3rd Bohr orbits is
For a Bohr atom, angular momentum of the electron is (n = 1, 2, 3 …)
Which of the following statements does NOT form a part of Bohr's model of hydrogen atom?
The value of a₀ (Bohr radius) in the expression for the radius of nth orbit of hydrogen atom (rₙ = n²a₀) is
Electronic energy is negative because
According to Bohr model, angular momentum of an electron in the 3rd orbit is
The Bohr orbit radius for hydrogen atom (n = 1) is 0.529 Å. The radius for the first excited state (n = 2) orbit is
Energy of electron of hydrogen atom in the second Bohr orbit is
The ionization energy of H atom is 13.6 eV. The ionization energy of Li²⁺ ion will be
The energy of an electron in the 3rd orbit of hydrogen atom is
If the threshold frequency of a metal for the photoelectric effect is ν₀, which of the following will NOT happen?
The threshold wavelength for the photoelectric effect on sodium is 5000 Å. Its work function is:
Ultraviolet light of 6.2 eV falls on an aluminium surface (work function = 4.2 eV). The kinetic energy (in joule) of the fastest electron emitted is approximately:
The minimum frequency ν₀, below which the photoelectric effect is not observed, is called
The kinetic energy of photoelectrons does NOT depend upon
The photoelectric effect shows:
Increasing the frequency of incident radiation in the photoelectric effect increases the:
In the photoelectric effect, the number of photoelectrons emitted is proportional to:
Einstein's theory of photoelectric effect is based on: