Question

The temperature of a room is ${77^ \circ }\,F$. What would it be on the Celsius scale?
A. ${25^ \circ }\,C$
B. ${45^ \circ }\,C$
C. ${60^ \circ }\,C$
D. ${350^ \circ }\,C$

Answer 1

Hint:Fahrenheit is a temperature scale mainly found in the United States, where the water freezing point is $32$ degrees and the water boiling point is $212$ degrees. This divides $180$ degrees from the boiling and freezing points of water. Thus, a degree on the scale of Fahrenheit is $1/180$ of the interval between the freezing point and boiling point. The freezing and boiling points of water are $100$ degrees apart on the Celsius scale. A ${1^ \circ }F$ temperature interval is equal to a $5/9$ degrees Celsius interval.

Complete step by step answer:
Ice point corresponds to the freezing point if water is equivalent to ${0^ \circ }C({32^ \circ }F)$, in which pure water and ice are in equilibrium. Steam point corresponds to the boiling point of fresh water equal to $100$ degree Celsius at which water and vapour are in equilibrium.

On the Celsius scale, the degree Celsius is a unit of temperature, a temperature scale known originally as the centigrade scale. On the Celsius scale, the degree Celsius can refer to a specific temperature or to a unit to indicate a difference or uncertainty between two temperatures. Relationship between Celsius and Fahrenheit scale is:
$
C = \dfrac{5}{9} \times \left( {F - 32} \right) \\
\Rightarrow C = \dfrac{5}{9} \times \left( {77 - 32} \right) \\
\Rightarrow C = \dfrac{5}{9} \times 45 \\
\therefore C = {25^ \circ }\,C \\ $
The temperature of a room is ${25^ \circ }\,C$ at ${77^ \circ }\,F$.

Hence, option A is correct.

Note:Here we have to remember the relationship between Celsius and Fahrenheit scale otherwise the answer would be wrong. Relationship between Celsius and Fahrenheit scale is: $C = \dfrac{5}{9} \times \left( {F - 32} \right)$.Celsius is a temperature measurement in which the melting point of water is $0$ degrees and the boiling point of water in the normal atmosphere is $100$ degrees, and is the mean barometric pressure at the mean sea level.