Inside the dust jacket of my lovely book about 40s electricity are quiz questions.


Here is one for Chris who knows about these things.


Q.3a, Estimate the number of gallons of water in a cylinder which is 1ft 8 inches diameter and 2ft 4 inches high. (I suppose that we ignore any dome, or assume a perfect cylinder).


b, How long will it take to heat the water in this cylinder from 40 degrees F. to 100 degrees F. if the immersion heater is rated at 3kW?


Z.