On the Celsius scale,the absolute zero of temperature is at .......... $^\circ C$.

The resistance of a thermometer is $100 \Omega$ at the triple point of water $(273 \ K)$ and is $300 \Omega$ at the melting point of gold $(873 \ K)$. The temperature at which the resistance of the thermometer is $200 \Omega$ is: (in $K$)

The saturation vapour pressure of water at $100^{\circ}C$ is ........ $mm$ of mercury.

Standardisation of thermometers is obtained with

Write the equation that gives the relation between $t_F$ and $t_C$.

What is a thermometer? What is a gas thermometer? Write its characteristics.