Physics

Red colour has the longest wavelength.

In automobiles, a bumper is the front-most or rearmost part, ostensibly designed to allow the car to sustain an impact without damage to the vehicle’s safety systems. They are not capable of reducing injury to vehicle occupants in high-speed impacts, but are increasingly being designed to mitigate injury to pedestrians struck by cars.

The total width of the depletion region is a function of applied reverse-bias and impurity concentration. Forward bias decreases the depletion region width whilst reverse bias increases it.