Question

What is the opposite of rise in temperature by ${5^0}C$
(A) $+ {5^0}C$
(B) $- {15^0}C$
(C) Fall in temperature by ${5^0}C$
(D) $+ {10^0}C$

Answer 1

Hint: Rise of temperature by a certain value is to be interpreted mathematically. The answer is to be devised by logical reasoning.

Complete step-by-step solution:
Given the problem we need to find the opposite of rise in temperature by ${5^0}C$.
Temperature is a physical property of matter that quantitatively expresses hot and cold.
Temperature can be measured quantitatively using a thermometer.
Thermometers are calibrated in various temperature scales.
The most common scales are the Celsius scale ( also called centigrade, denoted $^0C$ ), the Fahrenheit scale ( denoted $^0F$ ), and the Kelvin scale (denoted K).
In the problem the temperature is measured in Celsius scale.
We need to analyse every option in order to find the correct answer.
According to option (A) opposite of rise in temperature by ${5^0}C$is $+ {5^0}C$, which is not correct as the initial temperature is not known. So, we cannot assign a particular value on the Celsius scale.
Similarly, option (B) denotes the opposite of rise in temperature by ${5^0}C$ as $- {15^0}C$, which is also not correct as the initial temperature is not known. So, we cannot assign a particular value on the Celsius scale.
For the same reason as stated above, option (D) $+ {10^0}C$ is also rejected.
According to option (C) opposite of rise in temperature by ${5^0}C$ is fall in temperature by ${5^0}C$
which seems to be the correct answer as fall is the opposite of rise.
Hence option (C). Fall in temperature by ${5^0}C$ is the correct answer.

Note: Rise and fall of temperature can also be interpreted as increase or decrease in temperature with respect to a reference value. The verbal language of the problem should be read carefully and the most suitable answer should be chosen in problems like above.