Which of the following will rise the highest in the atmosphere?
Warm air rises higher. This is because gases expand more when they absorb heat further.
What is an anemometer?
An anemometer is a device used for measuring wind speed.
Which of the following is true of the 'eye' of a cyclone?
The 'eye of a cyclone is the least pressure area with very high speed winds revolving around it.
Which of the following plays an important role in the early-warning systems for cyclones?
The photographs taken by the satellites help in detecting cyclones.
Which of the following is the best thing to do during heavy lightning?
Lightning hits tall structures, water and metallic bodies easily. So, avoiding them will be safer.
During the formation of rain, what happens when water vapor changes to rain drops?
The energy contained in the gaseous form (vapour) is more than the energy contained in the liquid form (water). Therefore, when vapour changes to water it loses some heat.
How are sea and land breezes caused?
Sea and land breezes are caused because of the uneven heating of the earth through convection currents.
On the earth, the winds from the north and the south blow towards the equator. What can we understand from this?
Winds that are cold usually show lateral (sideways) movement while the ones that are warm show vertical movement. Since, the winds blow from the north and the south towards the equator, it must be hotter than the other places.
The winds on the earth do not flow in the exact "north to south" or "south to north" directions. Why?
The rotation of the earth from west to east (pulls) changes the north-south winds to northeast-southwest direction and the south-north winds to southeast-northwest direction.
What is created temporarily behind when a vehicle moves very fast?
When a vehicle moves very fast, a low pressure is produced temporarily and the wind nearby rushes in to fill its place.
From where do the monsoon winds come to India?
The winds coming from the southwest blow over the Indian ocean and bring lots of rains.
Upon heating, gases become lighter. Why?
Upon heating, the molecules in the gases go further away from each other and thus become lighter.
What is the best thing to do when strong winds blow over a hut having a weak thatched roof?
When winds blow over a weak thatched roof, it creates a low pressure over it and a high pressure inside the hut causing the roof to blow off. Opening the doors and windows reduces this pressure difference and prevents the roof from being blown off.
Which of these countries is most likely to be affected by cyclones?
Only Indonesia is nearer to the sea and most likely to be affected by cyclones.
Which of the following has the highest pressure?
Pressure is highest in a bottle or any container which is closed.
Which of the following is NOT affected by air pressure?
A drinking straw is used by creating a suction with your mouth. Actually this causes a decrease in air pressure on the inside of the straw. Since the atmospheric pressure is greater on the outside of the straw, liquid is forced into and up the straw.
Which of the following does NOT increase the humidity of the surrounding air?
Evaporation causes an increase in humidity, the amount of water vapour present in the air. Formation of dew drops on leaves is the result of condensation and not of evaporation.
"Water vapor in the atmosphere condenses to form clouds?: From this statement, what can be concluded?
Change of water vapour to water (condensation) takes place at a low temperature. Since, clouds are formed high up in the air, we can conclude that temperature decreases as we go higher in the atmosphere.
Which of the following shows that air exerts pressure?
The difference of air pressure between the surface of the liquid and inside the straw or an ink filler pushes the liquid up. Hence, both of them work on atmospheric pressure.
Warm air is lighter than cold air. Why?
Warm air is lighter than cold air because the air in contact with the hot surface of the earth gets heated up, so it expands and becomes lighter.