Context and question: Luminous efficacy of a light source may be defined in two ways. The radiant luminous efficacy (LER) is the ratio of the visible light flux emitted (the luminous flux) to the total power radiated over all wavelengths. The source luminous efficacy (LES) is the ratio of the visible light flux emitted (the luminous flux) to the total power input to the source, such as a lamp. Visible light is measured in lumens, a unit which is defined in part by the differing sensitivity of the human eye to different wavelengths of light. Not all wavelengths of visible electromagnetic energy are equally effective at stimulating the human eye; the luminous efficacy of radiant energy (LER) is a measure of how well the distribution of energy matches the perception of the eye. The units of luminous efficacy are "lumens per watt" (lpw). The maximum LER possible is 683 lm/W for monochromatic green light at 555 nanometers wavelength, the peak sensitivity of the human eye.
What may be defined in three ways?
Answer: unanswerable
Context and question: Arsenal's home colours have been the inspiration for at least three other clubs. In 1909, Sparta Prague adopted a dark red kit like the one Arsenal wore at the time; in 1938, Hibernian adopted the design of the Arsenal shirt sleeves in their own green and white strip. In 1920, Sporting Clube de Braga's manager returned from a game at Highbury and changed his team's green kit to a duplicate of Arsenal's red with white sleeves and shorts, giving rise to the team's nickname of Os Arsenalistas. These teams still wear those designs to this day.
What team in 1938 used the same style of kit, but in green?
Answer: Hibernian
Context and question: In an interview published by Vogue in April 2013, Beyonce was asked if she considers herself a feminist, to which she said, "that word can be very extreme... But I guess I am a modern-day feminist. I do believe in equality". She would later align herself more publicly with the movement, sampling "We should all be feminists", a speech delivered by Nigerian author Chimamanda Ngozi Adichie at a TEDxEuston conference in April 2013, in her song "Flawless", released later that year. She has also contributed to the Ban Bossy campaign, which uses television and social media to encourage leadership in girls.
Where was Beyonce quoted as saying that she is a modern-day feminist?
Answer:
Vogue