The frequency of radiation emitted when an electron falls from n=4 to n=1 in a hyddrogen atom will be:(given, ionisation energy of H=2.18*10^-18 J atom^-1 and h=6.625*10^-34 Js)

The wavelength of the first spectral line in Balmer series of spectrum of H-atom is:

Bohr's radius of H-atom is 0.529Å. What is the radius of 2^nd shell of He⁺ ?

If an electron, a proton and an α-particle have same de Broglie wavelengths, their kinetic energies are related to one another as :

√v of X-rays is plotted v/s atomic numbers of elements in Moseley's experiment. The slope of graph is( a & b are constants) :

When the letters shown have their usual meanings, the velocity of photoelectrons is:

The number of electrons in d-subshell of Cr²⁺ (Z=24) is not equal to:

When an electron jumps from 5th excited state to 2nd excited state in H-atom, the number of lines produced in Balmer series is :

The quantum numbers of 9th electron in the electronic configuration of fluorine (Z=9), are:

Which of the following does not have spherical as well as angular node?

The number of spherical nodes, angular nodes and nodal planes for ³p_z in proper order are:

If the uncertainties of position and momentum of a particle of mass m are equal, the uncertainty of velocity would be:

The dimensions of Planck's constant are the same as that of :

The ratio of ionisation energies of Li²⁺ and Be³⁺ is :

Which of the following has highest wavelength?

How many revolutions an electron will make in 2nd shell of He⁺ in one second?

For azimuthal quantum number l=3, the maximum number of electrons will be:

Among the following series of transition metal ions, the one where all metal ions have same 3d electronic configuration is:

The energy of 2nd Bohr's orbit of hydrogen atom is -328 kJ mol^-1. Hence, the energy of 4th Bohr's orbit would be:

The electronic configuration of N in HNO₂ (as per oxidation state) is:

If uncertainties of positions of an electron and a proton are equal, the ratio of uncertainties of their velocities will be:

When an electron is accelerated from rest through a potential V, its velocity is:

A metal sheet is irradiated separately with radiations of frequencies v1 and v2. If the ratio of the kinetic energies of photoelectrons is 1:x, the threshold frequency of metal is:

If 'r' is the radius of first Bohr shell in an atom, calculate the de Broglie wavelength in 3rd shell:

An object absorbs energy corresponding to wavelength 2400Å and emits two different radiations. The wavelength of one radiation is 6000Å. What is the wavelength of other radiation?

The kinetic energy of an electron in n^th of a unielectron species of atomic number Z is 13.6 Z²/n² eV. The potential energy of this electron in the same situation is:

The ratio of area covered by second orbit to the first orbit is:

The number of photons emitted by a 10 watt bulb in 10 seconds, if the wavelength of the light is 1000Å, is:

A bulb marked as 100 watt emits light of 4000Å. If 20% energy is emitted as light, how many photons are emitted in one second?

The atomic masses of He and Ne are 4 and 20 amu respectively. The value of the de Broglie wavelength of He gas at -73° C is 'M' times that of the de Broglie wavelength of Ne at 727° C. 'M' is :

Given, the mass of electron is9.11*10^-31 kg and Planck's constant is 6.626*10^-34 Js. The uncertainty involved in the measurement of velocity within a distance of 0.1 Å is:

The number of possible orientations of an electron in an atom is given by its:

The de Broglie wavelength of a particle of mass 1g and velocity 100 ms^-1 is:

The de Broglie wavelength associated with a ball of mass 1 kg having kinetic energy 0.5 J is:

The ground state energy of H-atom is -13.6 eV . When its electron is in the 1st excited state, its excitation energy is:

Two nuclei have their mass number in the ratio 1:3. The ratio of their nuclear densities would be:

The uncertainties in the velocities of two particles A and B are 0.05 and 0.02 ms-1 respectively. The mass of B is five times to that of the mass of A. What is the ratio of uncertainties

The de Broglie wavelength of a particle with mass 1 kg and velocity 100 ms^-1 is:

The maximum number of electrons in a subshell of an atom is determined by the following:

The energy of electron in first Bohr's orbit of H-atom is -13.6 eV. The possible energy value of the excited state for electron in Bohr's orbits of hydrogen is:

Total number of atomic orbitals in 4th energy level of an atom is:

Maximum numbers of electrons in a subshell with l=3 and n=4 is :

Which is maximum number of electrons that can be associated with the following set of quantum numbers n=3, l=1 and m=-1?

Calculate the energy in joule corresponding to light of wavelength 45 nm : (Planck's constant h=6.63*10^-34 Js; speed of light c=3*10⁸ ms-1)