The energy supply being cut-off, an electric heater element cools down to the temperature of its surrounding, but it will not cool further because

The energy supply being cut-off, an electric heater element cools down to a temperature of its surroundings but it will not cool further because

As difference of temperature of body and surroundings increases, rate of cooling

Choose the correct statement A: It is impossible to derive continuous supply of work by cooling a body to a temperature lower than that of the coldest of its surroundings. B: Heat engine can convert whole of the heat energy supplied to it into useful work.

"We supply electric current continuously to an electric heater. But the temperature of the heater remains constant after some time." Why ?

A liquid contained in a beaker cools from 80^(@)C to 60^(@)C in 10 minutes. If the temperature of the surrounding is 30^(@)C , find the time it will take to cool further to 48^(@)C . Here cooling take place ac cording to Newton's law of cooling.

A body cools at the rate of 1.5 °C/min when its temperature is 30 °C above that of the surrounding. At what temperature above the surrounding will it cool at the rate of 1 °C/min?

A body is heated to a temperature of 75^(@)C and is allowed to cool. If the temperature of the surrounding is 35^(@)C , then the temperature at which the rate of cooling will be exactly half of that initially will be