Question

A Kelvin thermometer and a Fahrenheit thermometer used to record temperature of melting metal, read the same. What will a Celsius thermometer read at that temperature?

• A. ${301.25}^{o}C$
• B. ${273}^{o}C$
• C. ${457}^{o}C$
• D. ${760}^{o}C$

Answer 1

The correct option is A ${301.25}^{o}C$

Let $t$ be the temperature , read same on Kelvin and Fahrenheit scale .

we have , $\frac{K-273}{100}=\frac{F-32}{180}$ ,

$\Rightarrow$ $\frac{t-273}{100}=\frac{t-32}{180}$ ,

$\Rightarrow$ $\frac{t-273}{5}=\frac{t-32}{9}$ ,

$\Rightarrow$ $9t-2457=5t-160$ ,

$\Rightarrow$ $4t=2297$ ,

$\Rightarrow$ $t=2297/4=574.25$

Therefore, temperature on Celcius scale will be $=574.25-273={301.25}^{o}C$