text: An simple-to-use small signal model for these elements is the piecewise linear model.
full_question: An simple-to-use small signal model for these elements is the piecewise linear model. Although it is normally treated as equal to one, the exponential term in an equation for these elements has an emission coefficient or ideality factor multiplying the thermal voltage. Smoothing capacitors are most commonly used by inserting them in parallel with one of these elements in a half-wave rectifier. These nonlinear elements have a "knee" point in their I-V curves at around 0.7 volts, beyond which the current rapidly increases to infinity. These elements are represented as a sideways triangle with a vertical line at its tip. For 10 points, name these circuit elements that permit current flow in only one direction.
first_sentence: An simple-to-use small signal model for these elements is the piecewise linear model.
raw_answer: silicon p-n diodes [prompt on p-n junctions]