Article: In the last two decades, photovoltaics (PV), also known as solar PV, has evolved from a pure niche market of small scale applications towards becoming a mainstream electricity source. A solar cell is a device that converts light directly into electricity using the photoelectric effect. The first solar cell was constructed by Charles Fritts in the 1880s. In 1931 a German engineer, Dr Bruno Lange, developed a photo cell using silver selenide in place of copper oxide. Although the prototype selenium cells converted less than 1% of incident light into electricity, both Ernst Werner von Siemens and James Clerk Maxwell recognized the importance of this discovery. Following the work of Russell Ohl in the 1940s, researchers Gerald Pearson, Calvin Fuller and Daryl Chapin created the crystalline silicon solar cell in 1954. These early solar cells cost 286 USD/watt and reached efficiencies of 4.5–6%. By 2012 available efficiencies exceed 20% and the maximum efficiency of research photovoltaics is over 40%.

Question: Who created the first solar cell using silver selenide in place of copper oxide?
Ans: Dr Bruno Lange


Article: A study conducted in 1972 and 1981, documented by Robert Ulrich, surveyed 23 surgical patients assigned to rooms looking out on a natural scene. The study concluded that patients assigned to rooms with windows allowing lots of natural light had shorter postoperative hospital stays, received fewer negative evaluative comments in nurses’ notes, and took fewer potent analegesics than 23 matched patients in similar rooms with windows facing a brick wall. This study suggests that due to the nature of the scenery and daylight exposure was indeed healthier for patients as opposed to those exposed to little light from the brick wall. In addition to increased work performance, proper usage of windows and daylighting crosses the boundaries between pure aesthetics and overall health.

Question: Who documented 23 surgical patients assigned rooms looking out on a natural scene?
Ans: Robert Ulrich


Article: Beginning with Immanuel Kant, German idealists such as G. W. F. Hegel, Johann Gottlieb Fichte, Friedrich Wilhelm Joseph Schelling, and Arthur Schopenhauer dominated 19th-century philosophy. This tradition, which emphasized the mental or "ideal" character of all phenomena, gave birth to idealistic and subjectivist schools ranging from British idealism to phenomenalism to existentialism. The historical influence of this branch of idealism remains central even to the schools that rejected its metaphysical assumptions, such as Marxism, pragmatism and positivism.

Question: In what century did Hegel write?
Ans: 19th


Article: This view is supported by a study of the region where these notions originated. Buddhism arose in Greater Magadha, which stretched from Sravasti, the capital of Kosala in the north-west, to Rajagrha in the south east. This land, to the east of aryavarta, the land of the Aryas, was recognized as non-Vedic. Other Vedic texts reveal a dislike of the people of Magadha, in all probability because the Magadhas at this time were not Brahmanised.[page needed] It was not until the 2nd or 3rd centuries BCE that the eastward spread of Brahmanism into Greater Magadha became significant. Ideas that developed in Greater Magadha prior to this were not subject to Vedic influence. These include rebirth and karmic retribution that appear in a number of movements in Greater Magadha, including Buddhism. These movements inherited notions of rebirth and karmic retribution from an earlier culture[page needed]

Question: Greater magadha stretched from Sravasti in the north-west to what area in the south-east?
Ans:
Rajagrha