What is the wavelength of a light ray that has a frequency of 7.4 E12 Hz?

How does the space charge width change with forward and reverse bias? also, calculate the space charge width for a reverse bias of 4v on a silicon pn junction at t = 300k and doping concentrations of na = 5x1015cm-3 , nd = 5x 1016 cm-3 .

Connie has $660,000 she wants to save. if the fdic insurance limit per depositor, per bank, is $250,000, which of these way is distributing her money between three banks will guarantee that all of her money is insured ?

(**i would really appreciate if this was answered soon** ) which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?