Question

The freezing point on a thermometer is marked as ${20}^{\circ }$ and the boiling point at as ${150}^{\circ }$. A temperature of ${60}^{\circ }$C on this thermometer will be read as

• A. ${40}^{\circ }$
• B. ${65}^{\circ }$
• C. ${98}^{\circ }$
• D. ${110}^{\circ }$

Answer 1

The correct option is C ${98}^{\circ }$

Temperature on any scale can be converted into other scale by $\frac{X-LFP}{UFP-LFP}$ = Constant for all scales
$\therefore$ $\frac{X-{20}^{\circ }}{{150}^{\circ }-{20}^{\circ }}=\frac{C-0^{\circ }}{{100}^{\circ }-0^o}$ $\Rightarrow$ X = $\frac{C\times {130}^{\circ }}{{100}^{\circ }}+{20}^{\circ }$ = $\frac{{60}^{\circ }\times {130}^{\circ }}{{100}^{\circ }}+{20}^{\circ }={98}^{\circ }$