Problem: LEDs have been developed by Seoul Semiconductor that can operate on AC power without the need for a DC converter. For each half-cycle, part of the LED emits light and part is dark, and this is reversed during the next half-cycle. The efficacy of this type of HP-LED is typically 40 lm/W. A large number of LED elements in series may be able to operate directly from line voltage. In 2009, Seoul Semiconductor released a high DC voltage LED, named as 'Acrich MJT', capable of being driven from AC power with a simple controlling circuit. The low-power dissipation of these LEDs affords them more flexibility than the original AC LED design.
What is so good about ac powered HP-LEDs?
The answer is the following: more flexibility

Problem: Of the five original great powers recognised at the Congress of Vienna, only France and the United Kingdom have maintained that status continuously to the present day, although France was defeated in the Franco-Prussian War and occupied during World War II. After the Congress of Vienna, the British Empire emerged as the pre-eminent power, due to its navy and the extent of its territories, which signalled the beginning of the Pax Britannica and of the Great Game between the UK and Russia. The balance of power between the Great Powers became a major influence in European politics, prompting Otto von Bismarck to say "All politics reduces itself to this formula: try to be one of three, as long as the world is governed by the unstable equilibrium of five great powers."
What 2 powers named in the 5 orignal great powers of the congress of vienna have maintained that status?
The answer is the following: only France and the United Kingdom

Problem: Also labeled an Orphist by Apollinaire, Marcel Duchamp was responsible for another extreme development inspired by Cubism. The ready-made arose from a joint consideration that the work itself is considered an object (just as a painting), and that it uses the material detritus of the world (as collage and papier colle in the Cubist construction and Assemblage). The next logical step, for Duchamp, was to present an ordinary object as a self-sufficient work of art representing only itself. In 1913 he attached a bicycle wheel to a kitchen stool and in 1914 selected a bottle-drying rack as a sculpture in its own right.
What two items did Duchamp attach together in 1913?
The answer is the following: a bicycle wheel to a kitchen stool

Problem: Commercial CSP plants were first developed in the 1980s. Since 1985 the eventually 354 MW SEGS CSP installation, in the Mojave Desert of California, is the largest solar power plant in the world. Other large CSP plants include the 150 MW Solnova Solar Power Station and the 100 MW Andasol solar power station, both in Spain. The 250 MW Agua Caliente Solar Project, in the United States, and the 221 MW Charanka Solar Park in India, are the world's largest photovoltaic plants. Solar projects exceeding 1 GW are being developed, but most of the deployed photovoltaics are in small rooftop arrays of less than 5 kW, which are grid connected using net metering and/or a feed-in tariff. In 2013 solar generated less than 1% of the worlds total grid electricity.
The largest solar power plant in the world is located in what desert?
The answer is the following:
the Mojave Desert