Context: Electrolytic capacitors use an aluminum or tantalum plate with an oxide dielectric layer. The second electrode is a liquid electrolyte, connected to the circuit by another foil plate. Electrolytic capacitors offer very high capacitance but suffer from poor tolerances, high instability, gradual loss of capacitance especially when subjected to heat, and high leakage current. Poor quality capacitors may leak electrolyte, which is harmful to printed circuit boards. The conductivity of the electrolyte drops at low temperatures, which increases equivalent series resistance. While widely used for power-supply conditioning, poor high-frequency characteristics make them unsuitable for many applications. Electrolytic capacitors will self-degrade if unused for a period (around a year), and when full power is applied may short circuit, permanently damaging the capacitor and usually blowing a fuse or causing failure of rectifier diodes (for instance, in older equipment, arcing in rectifier tubes). They can be restored before use (and damage) by gradually applying the operating voltage, often done on antique vacuum tube equipment over a period of 30 minutes by using a variable transformer to supply AC power. Unfortunately, the use of this technique may be less satisfactory for some solid state equipment, which may be damaged by operation below its normal power range, requiring that the power supply first be isolated from the consuming circuits. Such remedies may not be applicable to modern high-frequency power supplies as these produce full output voltage even with reduced input.

Question: What is one type of metal which the conducting plates in electrolytic capacitors are commonly made of?
Answer: aluminum

Question: What type of dielectric layer is used in electrolytic capacitors?
Answer: an oxide dielectric layer

Question: What happens to the conductivity of the electrolyte at low temperatures?
Answer: drops at low temperatures

Question: How can electrolytic capacitors be safely used after having been stored unused for a long time?
Answer: by gradually applying the operating voltage

Question: Why might the method gradually applying the operating voltage not be suitable to protect electrolytic capacitors in modern devices?
Answer: these produce full output voltage even with reduced input

Question: What is one type of metal which the conducting plates in electrolytic capacitors are never made of?
Answer: Unanswerable

Question:  What type of dielectric layer is never used in electrolytic capacitors?
Answer: Unanswerable

Question: What happens to the conductivity of the electrolyte at high temperatures?
Answer: Unanswerable

Question: How can electrolytic capacitors be safely used after having been used for a long time?
Answer: Unanswerable

Question: Why might the method gradually applying the operating voltage not be suitable to protect electrolytic capacitors in ancient devices?
Answer: Unanswerable