Ideal Gas Equation and Absolute Temperature

What are the advantages of gas thermometer?
 

What is gas thermometer is used for?

What is the value of absolute zero in Celsius scale?

The most commonly used gas used in a constant pressure gas thermometer is:

Write two main advantages of a constant volume gas thermometer over the liquid thermometer.

Classify the gas thermometers based on their principle of working.

At _____$°\mathrm{C}$, the pressure and volume of a gas theoretically reaches zero.

Absolute zero is 

Which one is the correct dimensional formula for universal gas constant.

Which one is the correct SI unit of universal gas constant.

What is the SI unit of universal gas constant.