Question: The most common symptom of LED (and diode laser) failure is the gradual lowering of light output and loss of efficiency. Sudden failures, although rare, can also occur. Early red LEDs were notable for their short service life. With the development of high-power LEDs the devices are subjected to higher junction temperatures and higher current densities than traditional devices. This causes stress on the material and may cause early light-output degradation. To quantitatively classify useful lifetime in a standardized manner it has been suggested to use L70 or L50, which are the runtimes (typically given in thousands of hours) at which a given LED reaches 70% and 50% of initial light output, respectively.
Try to answer this question if possible: What could cause early light-output degradation in LEDs?
Answer: higher junction temperatures
Question: According to Buddhist traditions a Buddha is a fully awakened being who has completely purified his mind of the three poisons of desire, aversion and ignorance. A Buddha is no longer bound by Samsara and has ended the suffering which unawakened people experience in life.
Try to answer this question if possible: What do unawakend people experience?
Answer: suffering
Question: Much of California consists of a Mediterranean climate, with sometimes excessive rainfall from October–April and nearly no rain the rest of the year. In the Pacific Northwest rain falls year-round, but is much heavier during winter and spring. The mountains of the west receive abundant precipitation and very heavy snowfall. The Cascades are one of the snowiest places in the world, with some places averaging over 600 inches (1,524 cm) of snow annually, but the lower elevations closer to the coast receive very little snow.
Try to answer this question if possible: During what time of the year does California receive the most rainfall?
Answer: October–April
Question: Victoria married her first cousin, Prince Albert of Saxe-Coburg and Gotha, in 1840. Their nine children married into royal and noble families across the continent, tying them together and earning her the sobriquet "the grandmother of Europe". After Albert's death in 1861, Victoria plunged into deep mourning and avoided public appearances. As a result of her seclusion, republicanism temporarily gained strength, but in the latter half of her reign her popularity recovered. Her Golden and Diamond Jubilees were times of public celebration.
Try to answer this question if possible: How many children did Queen Victoria and Prince Albert have?
Answer:
nine