Physics - Semiconductors Question with Solution | TestHub

A p-n junction diode allows current to flow in only one direction, so it is used as a rectifier.

A photodiode and a solar cell are p-n junction diodes that convert light energy into electrical energy.

A light-emitting diode (LED) is a p-n junction diode that emits light radiation when forward biased.

A p-n junction diode cannot amplify a signal. Amplification (increasing the amplitude of an a.c. signal) requires a transistor, which consists of two p-n junctions.

Answer: for increasing the amplitude of an a.c. signal.