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LEDs have also been used as a medium-quality voltage reference in electronic circuits. The forward voltage drop (e.g. about 1.7 V for a normal red LED) can be used instead of a Zener diode in low-voltage regulators. Red LEDs have the flattest I/V curve above the knee. Nitride-based LEDs have a fairly steep I/V curve and are useless for this purpose. Although LED forward voltage is far more current-dependent than a Zener diode, Zener diodes with breakdown voltages below 3 V are not widely available.

What LEDs have a very steep I/V curve?
Answer: Nitride-based LEDs
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Political unification returned in the mid-16th century, due to the efforts of Taungoo, a former vassal state of Ava. Taungoo's young, ambitious king Tabinshwehti defeated the more powerful Hanthawaddy in the Toungoo–Hanthawaddy War (1534–41). His successor Bayinnaung went on to conquer a vast swath of mainland Southeast Asia including the Shan states, Lan Na, Manipur, Mong Mao, the Ayutthaya Kingdom, Lan Xang and southern Arakan. However, the largest empire in the history of Southeast Asia unravelled soon after Bayinnaung's death in 1581, completely collapsing by 1599. Ayutthaya seized Tenasserim and Lan Na, and Portuguese mercenaries established Portuguese rule at Thanlyin (Syriam).

Before attempting to obtain political unification, what title did Taungoo,hold ? 
Answer: a former vassal state of Ava.
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Besides singing Madonna has the ability to play several musical instruments. She learned to play drum and guitar from her then-boyfriend Dan Gilroy in the late 1970s before joining the Breakfast Club line-up as the drummer. This helped her to form the band Emmy, where she performed as the guitarist and lead vocalist. Madonna later played guitar on her demo recordings. On the liner notes of Pre-Madonna, Stephen Bray wrote: "I've always thought she passed up a brilliant career as a rhythm guitarist." After her career breakthrough, Madonna focused mainly in singing but was also credited for playing cowbell on Madonna (1983) and synthesizer on Like a Prayer (1989). In 1999, Madonna had studied for three months to play the violin for the role as a violin teacher in the film Music of the Heart, before eventually leaving the project. After two decades, Madonna decided to perform with guitar again during the promotion of Music (2000). She took further lessons from guitarist Monte Pittman to improve her guitar skill. Since then Madonna has played guitar on every tour, as well as her studio albums. At the 2002 Orville H. Gibson Guitar Awards, she received nomination for Les Paul Horizon Award, which honors the most promising up-and-coming guitarist.

What instrument does Madonna play on her demo recordings?
Answer:
guitar