Question

A thermometer is graduated in mm. It registers - 3mm when the bulb of thermometer is in pure melting ice and 22mm when the thermometer is in steam at a pressure of one atm. The temperature in ${}^{\circ }C$ when the thermometer registers 13mm is

• A. $\frac{13}{25}\times 100$
• B. $\frac{16}{25}\times 100$
• C. $\frac{13}{22}\times 100$
• D. $\frac{16}{22}\times 100$

Answer 1

The correct option is B $\frac{16}{25}\times 100$

For a constant volume gas thermometer temperature in ${}^{\circ }centigrade$ is given as
$T_c=\frac{P-P_0}{P_{100}-P_0}\times {100}^{\circ }C$ $\Rightarrow$ $T_c=\frac{13-(-3)}{22-(-3)}\times {100}^{\circ }C=\frac{16}{25}\times 100$