Question

Temperature of an object increases by $80$ degrees on the Celsius scale. What are corresponding changes on the Fahrenheit scale and absolute scale?

• A. ${144}^{\circ }\text{F},80\text{K}$
• B. ${40}^{\circ }\text{F},144\text{K}$
• C. ${40}^{\circ }\text{F},40\text{K}$
• D. ${72}^{\circ }\text{F},80\text{K}$

Answer 1

The correct option is A ${144}^{\circ }\text{F},80\text{K}$

As $\Delta T={80}^{\circ }\text{C}$, we can choose any 2 temperatures , lets take $0{}^{\circ }\text{C}\&{80}^{\circ }\text{C}$ .

Now, we have to find corresponding $\Delta T_F$ in Fahrenheit scale
$T_{{}^{\circ }\text{C}}=\frac{5}{9}(T_{{}^{\circ }\text{F}}-32)$

Let $T_{F1}$ and $T_{F2}$ be the corresponding temperature on Fahrenheit scale.
Then, $0=\frac{5}{9}(T_{F1}-32)$
$\Rightarrow T_{F1}={32}^{\circ }\text{F}$
Similarly,
$80=\frac{5}{9}(T_{F2}-32)$
$\Rightarrow T_{F2}={176}^{\circ }\text{F}$
$\therefore \Delta T_{{}^{\circ }\text{F}}=176-32={144}^{\circ }\text{F}$

Also, we know $\Delta T_{\circ C}=\Delta T_K$
$\therefore \Delta T_K=80\text{K}$