Free electron theory

The main drawback of classical free electron theory was

• Collision between neighboring electrons neglected

• Collision between neighboring electrons was considered

• Electrons are said to be increasing potential

• Electrons are said to be in periodic potential

Who postulated quantum free electron theory

• Drude and Lorentz

• Bohr and sommerfield

• Bloch

• Kroning Penny

Which theorem states that free electrons move in periodic potential

• Classical free electron theory

• Quantum free electron theory

• Zone theory or band theory

• Einstein's theory

The electrical conductivity increases with

• Increase in number of free electrons

• Increase in mass and relaxation time

• Decrease in mass and increase of relaxation time

• Decrease in number of free electrons and relaxation time

The velocity with which free electrons move on the surface of metals under applied electric field is termed as

• Average velocity

• RMS velocity

• Drift velocity

• Escape velocity