Which two statements correctly describe the role of a semiconductor in a solar cell?
A. When the semiconductors become charged, current flows from
the negative one to the positive one.
B. The electrons freed from the semiconductors by light exit the cell
and never return.
C. When photons are absorbed, electrons from the semiconductor
are freed because of the photoelectric effect.
D. When the semiconductors become charged, current flows from
the positive one to the negative one.

The heater element of a 120 v toaster is a 5.4 m length of nichrome wire, whose diameter is 0.48 mm. the resistivity of nichrome at the operating temperature of the toaster is 1.3 × 10-6 ω·m. the toaster is operated at a voltage of 120 v. (a) what is the power drawn by the toaster? (b) if the cost of electricity is 12 ¢ per kilowatt-hour, and it takes 2 minutes to toast bread, how much does it cost for toasted bread? (c) when the heater element is at room temperature, is the resistivity in the nichrome wire greater than, less than, or equal to it’s resistivity when at operating temperature? explain.