PYQ Bank

What are noncentral nuclear forces ? Discuss qualitatively how the presence of a small noncentral component in the nuclear force can account for the nonvanishing quadrupole moment of deuteron.

State the three characteristic properties of strong, weak and electromagnetic forces distinguishing one from the other.

How much energy is required to separate {}_8^{16}\text{O} nucleus into its constituent nucleons ? What is the binding energy per nucleon for this nucleus ?

Write down the quark constituents of each of the following:

(i) \pi^+

(ii) K^+

(iii) \Delta^{++}

(iv) \Sigma^0

(v) \Omega^-

Write the semi-empirical mass formula pointing out the role of volume term, surface energy term, coulomb and symmetry energy correction terms.

What is meant by quark confinement ? Why are the masses of hadrons larger than the sum of the masses of their constituent quarks ?

Point out the interactions in which the following conservation laws are obeyed or violated

(i) Isotopic spin

(ii) Hyper charge

(iii) Lepton number

(iv) Charge conjugation

Write the quark contents and the quantum numbers (B, J, s, I_3) of the following hadrons : \bar{\Sigma}^-, \Xi^\circ, \Pi^+, \bar{K}^\circ

What are Stokes and anti-Stokes lines ? What is their importance in understanding the molecular structure ?

The first rotational line in the rotational spectrum of CO is observed at 3\cdot84235\text{ cm}^{-1}. Calculate the rotational constant B and the bond length.

In an NMR experiment, hydrogen atoms are subjected to a magnetic field of 5.0\ \mathrm{T}. Determine the difference in energy (\mathrm{kJ/mol}) between two spin states of the nuclei of hydrogen atom and the frequency of radiation required for NMR.

What is the main inference drawn from the Stern Gerlach experiment ? What would be the change in the result in the following cases :

(i) electron spin is \frac{3}{2}\hbar instead of \frac{\hbar}{2}.

(ii) a beam of neutral atoms is passed through a homogeneous magnetic field.

Explain Stokes and anti-Stokes Raman scattering with the help of energy level diagram. For a diatomic molecule, obtain expressions for transition energies of its Raman spectra with rotational fine structure and hence the wave numbers of the Stokes lines.

Consider two electrons system in (3p)^1(4s)^1 configuration. Derive the allowed energy states of the system in (i) LS coupling and (ii) jj coupling sketching the energy level diagram in each case. Name the interactions which are responsible for different splittings.

What is meant by Larmour precession ? Calculate the Larmour frequency for protons in a magnetic field of 1 Tesla.

Given the force constant of HCl molecule = 516\ \mathrm{N\,m}^{-1}, determine the wave number of the fundamental mode of vibration of the molecule. How many transition lines one can expect in the vibration spectra of HCl molecule at room temperature?

Explain why lines in some Raman spectra are found to be plane polarized to different extents even though the exciting radiation is completely unpolarized?

Show that the lines in the absorption spectra corresponding to the rotational transitions from two adjacent energy levels of a medium sized molecule at room temperature have comparable intensities.

State Franck-Condon principle. Define Franck-Condon factors. Using schematic diagram, explain the decay of excited states leading to the phenomena of fluorescence and phosphorescence.

Explain the principle of Nuclear Magnetic Resonance (NMR) with the help of an energy level diagram. Give examples of nuclei which exhibit NMR. What major inferences can be drawn from an NMR spectra?