Which of these best describes the concept of the rock cycle?

a) sedimentary rocks may be remelted several times

b) rocks move in circles on the earth as the earth rotates

c) rocks can be moved from place to place on the earth without changing

d) rocks are continually changing, and any type of rock may be
transformed into another type by appropriate processes

Describe how the fermi level changes with donor level, temperature and contact with p and n type semiconductors

Which best describes the first law of thermodynamics as compared to the second law of thermodynamics? a. the first law describes how thermal energy is conserved but not the direction it moves. b. the first law describes the direction thermal energy moves but not how it is conserved. c. the first law describes how thermal energy can be created but not how it can be destroyed. d. the first law describes how thermal energy can be destroyed but not how it can be created.

Three resistors are connected in series across a 15-v power supply. if the potential drops across resistors 1 and 2 are 4.1 volts and 3.1 volts, what is the exact potential drop (in volts) across resistor 3?