Question

What is the specific heat capacity of water?
(A) The amount of heat needed to raise its temperature by a certain amount.
(B) The amount of heat needed to raise its frequency by a certain amount
(C) The amount of heat needed to raise its amplitude by a certain amount
(D) None

Answer 1

Consider water as a system. The quantities that define the water or the system are its mass and temperature. Accordingly, various energy terms are defined using these quantities. The temperature of the water can be increased or decreased by many ways. Look for the term that is expressed in terms of the mass of the water presented as a system and also the change in temperature.

Complete step by step answer:
The transfer of energy between objects or bodies which results in the change in temperature of the bodies is called heat.Consider water as a system. When a certain amount of heat is given to the system, the temperature of the system increases. The amount of heat which will be absorbed by the system depends on the mass of the system, the change in the temperature and the type of material the system has, in our case, it is water.

The heat absorbed is proportional to the above-mentioned quantities. Let the heat absorbed be $Q$, mass of water be $m$ and change in temperature be $\Delta \theta$, mathematically, we have,
$Q \propto m \\\ \Rightarrow Q \propto \Delta \theta \\\ \Rightarrow Q \propto m\Delta \theta \\\ \therefore Q = sm\Delta \theta$
Here, $s$ is the specific heat capacity. $s = \dfrac{Q}{{m\Delta \theta }}$, as you can see that specific heat capacity has units of $Jk{g^{ - 1}}{K^{ - 1}}$. Which means that, it is the amount of heat required to change the temperature of the water by $\Delta \theta$.Hence, the specific heat capacity of water is the amount of heat needed to raise its temperature by a certain amount.

Hence, option A is correct.

Note: You should always keep in mind that the specific heat capacity of any body is defined as the amount of heat required to change the temperature of the body by a certain amount, mathematically, we have specific heat capacity as $s = \dfrac{Q}{{m\Delta \theta }}$. Remember that the specific heat capacity also depends on the material of the body, that is why it is specific.