Question

Freezing point of water in Celsius scale will be measured as
A. $0{}^\circ C$
B. $15{}^\circ C$
C. $25{}^\circ C$
D. $30{}^\circ C$

Answer 1

Firstly you may recall that the Celsius scale is one the scales that is used to measure temperature. After that you could remember the temperature range of this scale and thus identify the lower and higher fixed points. Then, you could see which of the given options gives the freezing point of water in Celsius scale which is also its lower fixed point.

Complete answer:
In the question, we are asked to find the freezing point of water in Celsius scale.
You may know that, we basically use three different scales for measuring temperature, Celsius scale being one among them. The temperature range of Celsius scale is known to be from $0{}^\circ C$ to $100{}^\circ C$. Therefore, we see that the lower fixed point of Celsius scale is $0{}^\circ C$. Here, you may recall that $0{}^\circ C$ is the temperature at which the ice melts and water freezes. So we could say that it is at $0{}^\circ C$ that water freezes.
Hence, option A is found to be the correct answer.

Additional information:
The other two temperature scales used are the Kelvin and Fahrenheit. The Fahrenheit scale is known to have 180 divisions that vary from $32{}^\circ F$ to$212{}^\circ F$, where $32{}^\circ F$ is the melting point of ice. For the Kelvin scale the melting point of ice or the freezing point of water is found to be at $273.15K$.

Note:
You may recall that the higher fixed point of Celsius scale which is $100{}^\circ C$ and is known to be the temperature at which water boils. If we were to measure the body temperature, it would be $37{}^\circ C$ in Celsius scale and $98.6{}^\circ F$ in Fahrenheit scale. If the temperature is found to be over $100.4{}^\circ F\left( 38{}^\circ C \right)$ then we could say that the person suffers from fever.