4. A particle limited to the x axis has the form of elsewhere. (1) Please find the probability that particle can be found between x=0.3 to 0.4. (5 %) (2) Find the expectation value of (x) of the particle's position (-1 to 1). (5%)

8. Please select "True" of "False" for the following descriptions. (7%) (1) In a n-type semiconductor, the number of holes in the valence band is much less than the number of electrons in the conduction band. (2) In a n-type semiconductor, the current is usually contributed more from electrons than holes. (3) In a p-type semiconductor, a small amount of an impurity that forms states located in the energy gap close to the edge of the conduction band. (4) The intrinsic carrier concentration of a certain semiconductor material with bandgap of 0.7 eV is usually smaller than that of a certain semiconductor material with bandgap of 1.I eV at room temperature. (5) A certain semiconductor with bandgap of 1 eV is transparent to all visible light. (6) The depletion region of a pn junction diode will be located less on the lightly-doped side than the heavily-doped side. (7) The tunnel diode will have a larger tunneling current if the doping levels of the pr junction are reduced.

4. A particle limited to the x axis has the form of elsewhere. (1) Please find the probability that particle can be found between x=0.3 to 0.4. (5 %) (2) Find the expectation value of (x) of the particle's position (-1 to 1). (5%)

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