A copper wire has a cross-sectional area of 0.80 × 10-6 m2. The number density of electrons for copper is 9.5 × 10^28 m-3. A current of 18 A flows through the wire. Calculate the mean drift velocity of the free electrons in the wire. *

An electron is trapped at a defect in a crystal. the defect may be modeled as a one-dimensional, rigid-walled box of width 1.00 nm. (a) sketch the wavefunctions and probability densities for the n 1 and n 2 states. (b) for the n 1 state, nd the probability of nding the electron between x1 0.15 nm and x2 0.35 nm, where x 0 is the left side of the box. (c) repeat (b) for the n 2 state. (d) calculate the energies in electron volts of the n 1 and n 2 states