III Semester CONDENSED MATTER PHYSICS

The Laue conditions of X-ray Diffraction is

• k – k’ = 2 π G  

• k – k’ = 2 G  

• k – k’ = G 

• none of the above

The phase velocity is given as

• V_p = K/ ω

• V_p = ω/K 

• V_p = ω λ /K 

• V_p = ω / λ K

The region K-value where – π/a < K < π/a in a monoatomic lattice vibration is known as

• first Brillouin zone

• second Brillouin zone

• third Brillouin zone

• none of the above

The vibration of the particles in the acoustical mode is

• longitudinal

• transverse

• both

• none of the above

Plasmon is a packet of energy in the

• Electric field

• Magnetic field

• Lattice vibration

• Plasma oscillation

The thermal conductivity ‘C_v’ of solid is given as

The thermal expansion <x> in solid is given as

• None of the above

Phonon is a packet of energy in the

• Electric field

• Magnetic field

• Lattice vibration

• All of the above

The quantum of the coupled phonon-photon transverse wave field is known as

• positron

• polariton

• electron

• plasmon

The energy ‘E(k)’ of the crystal in the tight binding approximations is given as