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.
• B.
• C.
• D.

Answer 1

The correct option is B

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