Question

Calculate the normal temperature of a human body in Celsius scale if it is $98.4\,^\circ F$ in Fahrenheit scale.
A) $37.50\,^\circ C$
B) $36.88\,^\circ C$
C) $36.50\,^\circ C$
D) $37.88\,^\circ C$

Answer 1

Hint: We have 3 prominent temperature scales to measure the temperature.
1] $^\circ F$ called the Fahrenheit scale
2] $^\circ C$ called the Celsius scale
3] K called the kelvin scale
The temperature measured from one temperature scale can be converted to the other temperature scale using conversion formulae.
We will be using the conversion formula in this question to convert the temperature from Fahrenheit to Celsius scale.

Complete step-by-step answer:
We have a conversion formula to convert measured temperature from Fahrenheit to Celsius scale, it is given below.
Let x be the measured temperature which in this case is $98.4\,^\circ F$,
Then $y\,^\circ C\, = \,(x\,^\circ F\, - 32)\, \times \,\dfrac{5}{9}$
Method to obtain Celsius from Fahrenheit scale:
1] Subtract 32 from the observed temperature on Fahrenheit scale.
2] Multiply the obtained number by the fraction $\dfrac{5}{9}$ .
Applying the conversion formula in our question, we get
Let $y\,^\circ C\, = \,[98.4\,^\circ F\, - 32]\, \times \,\dfrac{5}{9}$
$y\,^\circ C\, = \,66.4\, \times \dfrac{5}{9}$
So finally, we get
$y\,^\circ C\, = \,36.88\,^\circ C$

Therefore, Option B is the correct answer.

Note: Temperature is one of the seven fundamental quantities of physics. Its S.I. unit is kelvin[K]. The kelvin scale is universally used for measuring temperatures in chemical reactions, for checking heat liberated or absorbed during enthalpy changes. The Celsius scale is mostly used for measuring temperatures involved with physical changes, such as boiling of water, evaporation point, dew point, freezing point, etc. Fahrenheit scale is usually used to measure the temperature of the human body. The normal temperature range for the human body is $97\,^\circ F$ to $99\,^\circ F$. The most widely accepted normal temperature is $98.6\,^\circ F$. If one has a temperature over this range, then he\she is considered to have mild fever.
At -40 degrees temperature, both the scales, i.e. Fahrenheit and Celsius scales give the same reading since scales converge at this point.
Thus, we can say $ - 40\,^\circ F\, = \, - 40\,^\circ C$.