2021 Fall EE211B Quiz 3

A group of converged energy levels is called......

• Energy band

• Energy gap

• Forbidden gap

Electrons and holes are equal in magnitude but opposite in polarity

• True

• False

A current I = 200 mA flows in the wire below. What is the magnitude of the current density J?

• J = 4 mA/cm^2

• J = 2 mA/cm^2

• J = 1 mA/cm^2

• J = 5 mA/cm^2

The electric current produced due to the steady flow of electrons in one direction is called ( ) current.

• direct

• drift

• diffusion

The energy band in which free electrons exist is the

• first band

• second band

• conduction band

• valence band

The following E-k diagram shows electron distribution in the conduction band. Since there exists electrons in the conduction band, there is drift current flow.

• True

• False

What is the approximate energy gap between the valance band and conduction band of a semiconductor?

• 0eV

• 1eV

• 5eV

• 10eV

The material with the biggest forbidden gap is called

• Conductor

• Semi-conductor

• Insulator

For the energy-band diagrams shown, which one represents a material with the lowest high resistance?

• a

• b

• c