Which of the following statements is/are true/false? 1. By increasing the temperature and pressure, we can convert atmospheric gases into liquid state. 2. A hot dry day means that the atmospheric temperature is high and the air humidity is low. Both these factors lead to an increase in the rate of evaporation and thus a large amount of cold formation.

Which of the following statements is/are true/false? 1. By increasing the temperature and pressure, we can convert atmospheric gases into liquid state. 2. A hot dry day means that the atmospheric temperature is high and the air humidity is low. Both these factors lead to an increase in the rate of evaporation and thus a large amount of cold formation. Correct Answer Only 2 is true.

The correct answer is Only 2 is true.

Key Points

• The gases can be converted into liquids by bringing their particles closer, so atmospheric gases can be liquified either by decreasing temperature or by increasing pressure.
  • Hence statement 1 is incorrect.
• On a hot dry day, the temperature is high and humidity is less, which helps in better evaporation.
• Due to the higher rate of evaporation, it gives a better cooling effect.
  • Hence statement 2 is correct.

Additional Information

•  Hygrometer :
  • A hygrometer is an instrument used to measure the amount of water vapour in the air, in soil, or in confined spaces. 
  • Humidity is the measure of the amount of moisture in the air.
  • Hygrometer works on the phenomenon called evaporative cooling.
  • When water evaporates from any surface, it becomes cool because water molecules take heat energy from the surface during evaporation.
  • Due to this cooling effect wet-bulb always shows low temperature than a dry bulb.
• Manometer :
  • Manometers are devices used for measuring the pressure at a point in a fluid, by balancing the column of fluid by the same or another column of fluid. 
  • The most common form of the manometer is the conventional mercury barometer used to measure atmospheric pressure.