## 1. The valence electrons do not directly determine the following property of a metal

## 2. The solid phase of an element follows van der Waals bonding with inter-atomic potential $$V\left( r \right) = - \frac{P}{{{r^6}}} + \frac{Q}{{{r^{12}}}}$$ where, P and Q are constants. The bond length can be expressed as

## 3. A system containing N non-interacting localized particles of spin $$\frac{1}{2}$$ and magnetic moment $$\mu $$ each is kept in constant external magnetic field B and in normal equilibrium at temperature T. The magnetization of the system is

## 4. In a cubic crystal, atoms of mass M_{1} lie on one set of planes and atoms of mass M_{2} lie on planes interleaved between those of the first set. If C is the forte constant between nearest neighbour planes, the frequency of lattice vibrations for the optical phonon branch with wave vector k = 0 is

_{1}lie on one set of planes and atoms of mass M

_{2}lie on planes interleaved between those of the first set. If C is the forte constant between nearest neighbour planes, the frequency of lattice vibrations for the optical phonon branch with wave vector k = 0 is

## 5. If the ionic radii of Mn and S are 0.80 and 0.184 nm respectively, the structure of MnS will be

## 6. An external magnetic field of magnitude H is applied to a type-I superconductor at a temperature below the transition point. Then which one of the following statements is not true for H less than the critical field H_{c}?

_{c}?