Hello,
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Yes, general  awareness and current affairs are one and same. General awareness is also called with the name current affairs, which means knowledge of awareness in the daily life style, it includes all the things like economy, business, sports etc.,
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Now GA can't be written as GK. GA and GK are 2 different concepts. GA in means general awareness which also means current affairs, GK in means general knowledge is all about Information which has been recorded in the past or the information of past.
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In simple, when some kind of incident happened on the particular present day it's called current affairs and  if the particular day been passed and the incident happened is no more a latest news it's called general knowledge.
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Hope you understood, if not please ask us with any further doubts. Thank you