D2O has maximum density at
9°C
11.6°C
15.9°C
20°C
D2O has maximum density at 11.6∘C
Density of water is maximum at :
(a) 0∘C (b) 100∘C
(c) 4∘C (d) 15∘C
An ideal heat engine exhausting heat at 77∘C is to have a 30% efficiency. It must take heat at