Which of the following represents the correct time-temperature curve when a block of metal is heated above room temperature & then left to cool in the room following Newton's law of cooling in which the rate of temperature drop will go on decreasing with the passage of time.
In case of a, centrifugal pump, the ratio h1/h2 is termed as the __________ efficiency (where, h1 = actual measured head & h2 = head imparted to the fluid by impeller).