This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.
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Question: Passage: In manufacturing the glass bulb, a type of "ribbon machine" is used. A continuous ribbon of glass is passed along a conveyor belt, heated in a furnace, and then blown by precisely aligned air nozzles through holes in the conveyor belt into molds. Thus the glass bulbs are created. After the bulbs are blown, and cooled, they are cut off the ribbon machine; a typical machine of this sort produces 50,000 bulbs per hour. The filament and its supports are assembled on a glass stem, which is fused to the bulb. The air is pumped out of the bulb, and the evacuation tube in the stem press is sealed by a flame. The bulb is then inserted into the lamp base, and the whole assembly tested.

Answer: What type of machine is not used in manufacturing light bulbs?

Question: Passage: Of Alaska's 2010 Census population figure of 710,231, 20,429 people, or 2.88% of the population, did not live in an incorporated city or census-designated place. Approximately three-quarters of that figure were people who live in urban and suburban neighborhoods on the outskirts of the city limits of Ketchikan, Kodiak, Palmer and Wasilla. CDPs have not been established for these areas by the United States Census Bureau, except that seven CDPs were established for the Ketchikan-area neighborhoods in the 1980 Census (Clover Pass, Herring Cove, Ketchikan East, Mountain Point, North Tongass Highway, Pennock Island and Saxman East), but have not been used since. The remaining population was scattered throughout Alaska, both within organized boroughs and in the Unorganized Borough, in largely remote areas.

Answer: In 2010, what percent of Alaska's population did not live in a city or CPD?

Question: Passage: BBC TV was renamed BBC1 in 1964, after the launch of BBC2 (now BBC Two), the third television station (ITV was the second) for the UK; its remit, to provide more niche programming. The channel was due to launch on 20 April 1964, but was put off the air by a massive power failure that affected much of London, caused by a fire at Battersea Power Station. A videotape made on the opening night was rediscovered in 2003 by a BBC technician. In the end the launch went ahead the following night, hosted by Denis Tuohy holding a candle. BBC2 was the first British channel to use UHF and 625-line pictures, giving higher definition than the existing VHF 405-line system.

Answer:
What channel was launched that caused BBC TV to be renamed BBC2?