Q.18 A cold storage plant is used for storing 50 tonnes of apples in perforated plastic crates. During the
storage, apples are cooled down from 28°C to storage temperature of 2°C. (Specific heat of the
apple = 0.874 kCal kg-1
°C-1
). If the required cooling is attained in 16 hours, the refrigeration plant
capacity (in Tons) is
(A) 19 (B) 24 (C) 29 (D) 32
Q.19 An actively growing culture of Acetobacter aceti is added to the vigorously aerated fermented fruit
juice medium containing 10 g l
-1
ethanol to produce vinegar. After some time, the ethanol
concentration in the medium is 0.8 g l
-1
and acetic acid produced is 8.4 g l
-1
.

What is the conversion
efficiency of the process with respect to theoretical yield?
(A) 30 (B) 50 (C) 70 (D) 90