Properties of air - class-VIII
When a vehicle travels very fast, a region of ______ is created temporarily just behind it.
Which of the following principle shows that if you increase air speed its pressure will decrease?
Increase in air speed is associated with ______________ .
A piece of paper is kept on the table. You have to lift it from the table by blowing high-speed air over it. In which direction will you blow the air?
Two pieces of papers are held parallel. Air is blown with a high speed in between them. Which of the following phenomena will be observed?
In normal conditions, atmospheric pressure varies with__________
At a high altitude the pressure is ___________.
The doldrums are in the _______________.
In the Earth's atmosphere, the atmospheric pressure ________.
Which of the following is the unit of Atmospheric pressure?
A column of air 1 sq. cm. in cross-sectional area extending from sea-level to the top of the atmosphere weights approximately ______.
The pressure and wind systems are actually the impact of Lithosphere and Hydrosphere on ______.
What is the level of mercury at normal atmospheric pressure?
The atmospheric pressure decreases at the rate of ______________.
When the temperature increases atmospheric pressure _________.
As one goes up from earth's surface, the temperature of air:
Fog can be defined as:
Which of the following statements is true regarding the properties of air?
Which of the following can show the direction of wind ?
Which of the following is not true about air?
Air can be separated into components by:
Which of the following is not true about air?
Which gas in the air is essential for burning of wood?
Which of the following is a property of air?
The experiment conducted using glass filled with water and card board indicates that _________.
Which of the following is an air pollutant?
Which of the following doesn't show that air exerts pressure?
What is the best thing to do when strong winds are blowing over a hut having a weak thatched roof?
During the takeoff of an aeroplane there is a _____________pressure on the top and a _____ pressure below.
Overhead cables need not be insulated because :
Water drops freeze and fall as:
The humidity of a place:
Which of the following plays a major role in the formation of a thunderstorm?
Which of the following are the uses of air?
Mountaineers carry oxygen cylinders with them because:
Which of the following statements is true regarding the properties of air?
The power of diffusion is:
Which of the following statement is/are correct ?
Cyclones become very destructive in area of Bay of Bengal during early November because of _________.