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Describe an activity to demonstrate that warm air is lighter than cool air.

The experiment to test that warm air is lighter than cool air is:- Take two paper bags of the same size. Hang the two bags in the inverted... View Article

Suggest some precautions to be taken to prevent the roof of a tin sheet from flying away during a fierce wind storm

Some precautions to prevent the roof of a tin sheet from flying away during a fierce wind storm are given below: a) We should screw it tight. The... View Article

When strong/high-speed wind blows, an umbrella held upright at times gets upturned. Explain the reason.

High speed wind passing over the umbrella creates low pressure. Therefore, the umbrella upturns high-speed winds have low pressure due to... View Article

Paheli kept an empty bottle made of plastic inside a refrigerator. After few hours, when she opened the refrigerator she found the bottle had collapsed. Explain the possible reason.

The air inside the bottle contracts due to low temperature hence the bottle collapses due to the outside pressure. When Paheli kept the closed... View Article

A flag mounted on a flag post near the sea coast flutters in the direction of sea. At what time of the day does this happen – at midnight or in the afternoon?

In this scenario, the flag will flutter in the direction of sea when it is midnight because at nighttime the sea becomes hotter than land... View Article

Figure shows a diagrammatic representation of trees in the afternoon along a sea coast. State on which side is the sea; A or B? Give reasons for your choice.

The sea is on the side ‘B’ because at the daytime the wind is coming from that side and as we know that there is sea breeze when... View Article

A flat in Mumbai with a balcony facing the sea has some clothes hung on a clothesline in the balcony. Towards which direction the clothes will be blown in the afternoon? Explain.

In the afternoon time the land gets heated much faster than sea and hence the air above the land traps heat and rises up by getting warmed and... View Article

Why is it advisable not to shut all the doors and windows during a storm?

In order to avoid the roof from getting blown away due to the low pressure created by heavy wind. Keeping the doors and windows closed helps to... View Article

To expel hot air out of the kitchen, ‘A’ has an exhaust fan fitted on the window of her kitchen and ‘B’ has a similar exhaust fan fitted on the wall near the ceiling of her kitchen. Which of the exhaust fan will expel the hot air more effectively? Explain why?

In the kitchen of 'B' ,warm air rises up and her exhaust fan is at standard height as comparison to, A. so, it will expel the hot air more... View Article

State whether the following statement is True or False. Warm air is lighter than cool air.

False Warm air is lighter than cold air because they have more heat energy, which results in the increase in distances between the molecules.... View Article

State whether the following statement is True or False. The coastline of India is not vulnerable to cyclones.

False The coastlines of India are highly vulnerable to cyclones and also the east coast is more vulnerable to cyclones with high speed and with... View Article

State whether the following statement isTrue or False. A very high-pressure system, with very high-speed wind surrounding it forms a cyclone.

False A cyclone is a natural disaster caused by the warming of air by water vapors through ocean and revolving of high-speed winds around a... View Article

State whether the following statement is True or False: If wind flows from land to the ocean, then it is daytime.

False. If wind flows from ocean to the land then it is daytime and is called sea breeze, because in daytime the land gets heated and the air... View Article

Fill in the blanks. (i) Air around us exerts ______ . (ii) The moving air is called _ . (iii) The main cause of wind movement is uneven _ on the earth. (iv) High speed wind can cause cyclone in regions of _____ pressure.

(i). Pressure (Atmospheric pressure) We know that particles in the air keep on moving and they never stop the same case as in liquids , The... View Article

Name the ocean which is mainly responsible to bring rain-bearing monsoon winds to Kerala coast in June every year?

The Indian Ocean is the main reason for monsoon because due to sea breeze phenomena the warm air above land rises up and the cool air above the... View Article

Why is Chandigarh unlikely to be affected by a cyclone?

Chandigarh is most unlikely to be affected by cyclone because it is not near to coastal line and has no sea or ocean near it, as it is surrounded... View Article

A curtain is hanging at the entrance of a room. A long corridor runs at right angles to the door, that is parallel to the curtain. If a strong wind blows along the corridor, the curtain will (a) get pushed inside the room. (b) get pushed outside the room. (c) get collected towards one end/swirled. (d) remain unaffected.

(b) get pushed outside the room. At high-speed winds have low pressure due to the scattering of particles it possesses and as the one side of... View Article

Which of the following place is most likely to be affected by a cyclone? (a) Mumbai (b) Puri (c) Goa (d) Porbandar

b) Puri East coast is more likely to face cyclones with great speed(intensity) and number of cyclones than the west coast and except Puri all... View Article

Following are precautions one must take in case a storm is accompanied by lightning. (i) Do not take shelter under a tree. (ii) Do not take shelter under an umbrella with a metallic end. (iii) Do not take shelter in open garages, storage sheds, etc. (iv) Do not take shelter in a bus in the open. Which one of these is not correct? (a) (i) (b) (ii) (c) (iii) (d) (iv)

(d) (iv) Do not take shelter in a bus in the open Buses are made up of metals from outside and hence when the lighting strikes the bus it would... View Article

Figure shows a child blowing air with a straw near the opening of another straw which has its other end in a soft drink bottle. It was observed that the level of the soft drink in the straw rises up as soon as air is blown over its open end. Which one of the following best explains the reason for the rise in the level of the drink? (a) The blowing of air decreases pressure over the opening of the straw. (b) The straw of the soft drink bottle collapses when air is blown over its open end. (c) The blowing of air warms up the air inside the straw. (d) The blowing of air increases the pressure on the surface of the soft drink in the bottle.

The answer is (a) Blowing of air decreases pressure over the opening of the straw. Decreased pressure over the opening of the straw makes the... View Article

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