Efficiency of a Carnot cycle is `75%`.If temperature of the hot reservoir is `727^@C`, calculate the temperature of the cold reservoir.

The temperature gradient of a rod of length 1 m is 60^@C//m . If the temperature of the hot end is 30^@C the temperature at the other end is

The efficiency of a Carnot cycle is 1/6 . If on reducing the temperature of the sink by 65^@C , the efficiency becomes 1/3 , find the initial and final temperatures between which the cycle is working.

Efficiency of a Carnot engine is 50% when temperature of outlet is 500 K . In order to increase efficiency up to 60% keeping temperature of intake the same what is temperature of outlet?

An engine has an efficiency of 1/6 . When the temperature of sink is reduced by 62^(@)C , its efficiency is doubled. Temperature of the source is

A reversible engine converts one fifth of heat which it absorbs from source into work. When the temperature of the sink is reduced by 70^@ , its efficiency is doubled. Calculate the temperature of the source and the sink .

If the co - efficient of performance of a refrigerator is 5 and operates at the room temperature (27^@C ) , find the temperature inside the refrigerator.

The pressure of a gas in a closed vessel is increased by 0.4%, if the temperature of the gas is increased by 1^@C , the initial temperature of the gas is

Energy is emitted from a hole in an electric furnace at the rate of 20W when that temperature of the furnace is 727^@C . What is the area of the hole ( sigma = 5.7 xx 10^-8 Js^-1m^-2K^-4 )

Read the following paragraph and answer the questions: If heat is exchanged between a hot and cold object, the temperature of the cold object goes on increasing due to gain of energy and the temperature of the hot object goes on decreasing gue to loss of energy. The change in temperature continues till the temperatures of both the objects attain the same value. In this process, the cold object gains heat energy and the hot object loses haet energy. If the system of both the objects is isolated from the environment by keeping it inside a heat resistance box (meaning that the energy exchange takes place between the two objects only ), then no energy can flow from inside the box or come into the box. Heat transferred from where to where?

Read the following paragraph and answer the questions: If heat is exchanged between a hot and cold object, the temperature of the cold object goes on increasing due to gain of energy and the temperature of the hot object goes on decreasing gue to loss of energy. The change in temperature continues till the temperatures of both the objects attain the same value. In this process, the cold object gains heat energy and the hot object loses haet energy. If the system of both the objects is isolated from the environment by keeping it inside a heat resistance box (meaning that the energy exchange takes place between the two objects only ), then no energy can flow from inside the box or come into the box. How will you state the principle briefly?