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Q.
A developer used in photography is
AFMCAFMC 2010
Solution:
A developer is a mild reducing agent. Ferrous oxalate, an alkaline solution of quinol, metal or amidol are some common developers. A developer in photography reduces the $AgBr$ to $Ag$ as
$ AgBr + \text{developer} \rightarrow Ag + HBr + \text{oxidised developer}$