Assume that an n-type semiconductor is uniformly illuminated, producing a uniform excess generation rate g 7.5 - 101 cm leading to a steady-state excess minority hole concentration of op = 1.5- 1015 [cm31. the electron and hole mobilities at room temperat are n1350 [cm2 - v-1. sand u 480 [cm2. v-1.s a) determine the excess minority carrier lifetime tp0. give the answer in seconds s. 0.2*10a-4 0.2 10 4 in the dark, the above mentioned semiconductor's conductivity at room temperature is oo = 0.41 s. cm 11. b) calculate the conductivity under uniform illumination. give the answer in [s -11and two decimal numbers.

When you push downward on a book at rest on a table, you feel an upward force. does this force depend on friction? defend your answer.

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.

Antireflective coatings on solar cells are often made by applying a thin film of silicon nitride (sinx), which has an index of refractive of 1.2, on the top of the silicon solar cell, which has a refractive index of about 3.5. however, the sun emits radiation of various wavelengths which the solar cell absorbs, and the antireflective coating can only absolutely minimize the reflection of one of these wavelengths. the coating thickness is chosen to reduce the reflection of green/yellow light (e = 2.2 ev), which is the most intense color in the solar spectrum (shown below). which of the following coatings would minimize reflection of green/yellow light? the answer is 820 nm how? what is the angular width of the central maximum of an electron traveling at 2 x 108 m/s going through a single slit of width 1 mm.