Unit 5 - Practice Quiz

1 In the classical free electron theory, the electrons in a metal are assumed to behave like:

2 Which of the following is a drawback of the Classical Free Electron Theory?

3 The drift velocity is related to the applied electric field and mobility by the relation:

4 Diffusion current in a semiconductor is caused by:

5 The Einstein relation relating the diffusion coefficient and mobility is given by:

6 The Fermi energy () of a metal at 0 K is defined as:

7 The Fermi-Dirac distribution function represents:

8 Mathematically, the Fermi-Dirac distribution function is given by:

9 At temperature K, what is the probability of occupancy of the Fermi energy level ()?

10 The density of states for free electrons in a three-dimensional metal is proportional to:

11 According to the Band Theory of Solids, the energy gap () in an insulator is approximately:

12 In a conductor (metal), the valence band and conduction band:

13 At 0 K, a pure intrinsic semiconductor behaves as:

14 The position of the Fermi level in an intrinsic semiconductor at absolute zero is located:

15 In an N-type semiconductor, the Fermi level at 0 K lies:

16 In a P-type semiconductor, the impurity atoms added are called:

17 As temperature increases, the Fermi level in an N-type semiconductor:

18 Which of the following represents the Law of Mass Action for semiconductors?

19 A Direct Band Gap semiconductor is one where:

20 An example of an Indirect Band Gap semiconductor is:

21 Recombination of an electron and hole in a Direct Band Gap semiconductor results primarily in:

22 The concept of Effective Mass () accounts for:

23 Mathematically, the effective mass is related to the energy-wave vector () curvature by:

24 Near the top of the valence band, the effective mass of an electron is:

25 A 'hole' in solid state physics is best described as:

26 The Hall Effect is the production of a voltage difference across an electrical conductor, transverse to an electric current and to an applied:

27 The Hall coefficient is given by the relation:

28 If the Hall coefficient is negative, the majority charge carriers are:

29 The Hall voltage generated in a slab of thickness , carrying current in a magnetic field , is:

30 Which of the following is NOT an application of the Hall Effect?

31 The Hall angle is the angle between:

32 The Fermi temperature is related to Fermi energy by:

33 In the derivation of Hall effect, at equilibrium, the magnetic Lorentz force () is balanced by:

34 The mobility of holes () is generally _____ than the mobility of electrons () in the same semiconductor.

35 For an intrinsic semiconductor, the Hall coefficient is:

36 The Wiedemann-Franz law states that the ratio of thermal conductivity () to electrical conductivity () is proportional to:

37 The unit of Hall coefficient is:

38 If the effective mass of an electron is small, the curvature of the energy band is:

39 Which statistics are applicable to electrons in a solid?

40 The Fermi level in a P-type semiconductor at room temperature is:

41 The probability that an energy level is occupied by a hole is given by:

42 In the free electron gas model, the potential energy of an electron inside the metal is assumed to be:

43 The mean free path of an electron is defined as:

44 Electrical conductivity () is given by:

45 Which material is typically used for making LEDs?

46 At absolute zero, the electrical conductivity of a pure metal is:

47 The total current density in a semiconductor is the sum of:

48 The value of Fermi function ranges from:

49 In a p-type semiconductor, the minority carriers are:

50 The dependence of Fermi energy on electron density in a metal at 0 K is: