The expected answers were:
(a)  Feedback: is the process of taking a fraction of a system output back to the input.
(b)  A closed loop control system is one in which the control action is dependent on the desired output whereas the open loop control system is one in which the control action is independent of the desired output.
(c)  Characteristics of feedback
                     (i)   Increased accuracy
                    (ii)   Improved stability
                    (iii)   Increased bandwidth
                   (iv)   Reduce noise
The question was on control circuits. A handful attempted the question. The performance was average.
Despite the question being a regular feature in  this paper, in part(a), majority defined feedback well while in part(b), very many could not distinguish between closed loop(involving feedback) and open loop(no feedback) systems. In part(c), the response was reported fair enough.