Question 13.
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 due 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 heat energy. If the system of both the objects is isolated from the environment by keeping it inside a heat resistant 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.
i. Heat is transferred from where to where?
ii. Which principle do we learn about from this process?
iii. How will you state the principle briefly?
iv. Which property of the substance is measured using this principle?
Answer:
i. Heat energy exchange takes place between the two objects only.
Because is system is isolated (has no interaction with surroundings) so no energy can flow from inside the box or come into the box.
ii. The principal which we learnt from the process is:
Heat energy lost by the hot object = Heat energy gained by the cold object.
iii. In the principle:
⇒ The cold objects gain heat energy and the hot object loses heat energy.
⇒ If the system become isolated (by using a heat resistant box), then the heat energy takes place between the two objects only.
⇒ As a result, no energy can flow from inside the box or come into the box.
⇒ In this situation, we get the following principle
Heat energy lost by the hot object = Heat energy gained by the cold object.
iv. The specific heat of the substance is measured using this principle:
⇒ The specific heat of the substance is measured by mixing method.
⇒ For this, calorimeter is used.
