Sometimes it is said that "heat is developed" in a resistance when there is an electric eurrent in it .Recall that heat is defined as the energy being transferred due to the temperature difference, Is the statement under quotes technically correct?

Heat is the transfer of energy between two objects with different temperature.

Assertion (A) : Heat energy is transferred from one body to another due to a temperature difference between them. Reason (R) : Heating a substance causes a rise in temperature.

The constant A in the Richardson-Dushman equation for tungsten is 60 xx 10^(4) A m^(-2) . The work function of tungsten is 4.5 eV . A tungsten cathode having a surface area 2.0 xx 10^(-5) m^2 is heated by a 24 W electric heater. In steady state, the heat radiated by the cathode equals the energy input by the heater and the temperature becomes constant. Assuming that the cathode radiates like a blackbody, calculate the saturation current due to thermions. Take Stefan constant = 6 xx 10^(-8) W m^(-2) K^(-4) . Assume that the thermions take only a small fraction of the heat supplied.

Read the following paragraph carefully and answer the following question . If the 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 due to loss of energy . The change in temperature continues till the tempertaures of both the object attain the same value . In the process, the cold object gains heat energy and the hot object lose heat energy . If the system of both the object is isolated form the environment by keeping it inside a heat resistance box ( meaning that the energy exchange takes place between the two object only), then no energy can flow from inside the box or come into the box. Which principle do we learn about from this process ?

A cubical box of volume 216cm^(3) is made up of 0.1cm thick wood, The inside is heated electrically by 100W heater. It is found that the temperature difference between the inside and the outside surface 5^(@)C in steady state . Assuming that the entire electrically energy spent appears as heat, find the thermal conductivity of the material of the box.

Read the following paragraph carefully and answer the following question . If the 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 due to loss of energy . The change in temperature continues till the temperatures of both the the object attain the same value . In the process, the cold object gains heat energy and the hot objet lose heat energy . If the system of both the object is isolated from the environment by keeping it inside a heat resistance box ( meaning that the energy exchange takes place between the two object only), then no energy can flow from inside the box or come into the box. Heat is transferred from where to where ?

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

Read the following paragraph carefully and answer the following question . If the 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 due to loss of energy . The change in temperature continues till the temperatures of both the the object attain the same value . In the process, the cold object gains heat energy and the hot objet losec heat energy . If the system of both the object is isolated from the environment by keeping it inside a heat resistance box ( meaning that the energy exchange takes place between the two object only), then no energy can flow form inside the box or come into the box. Which property of the substance measured using principle of heat exchange?.

Assertion: The process of transferring heat energy from lower temperature to higher temperature is called cooling. Reason : The mass of the system is not altered when it is cooled.