Q1Multiple choice
A fire alarm usually detects smoke in case of fire. Where should such an alarm be placed in a room?
- (a)Near the door
- (b)On the floor
- (c)On any wall
- (d)On the ceiling
Show answer
(d) On the ceiling
Chapter 8
Class 7 Science · 22 questions · 21 with answers
Questions
Q2Multiple choice
Four schematic diagrams are shown in Figure 8.1 to depict the direction of sea breeze. Which of them gives the correct direction?
This question refers to a figure in the original PDF.
- (a)
- (b)
- (c)
- (d)Fig. 8.1
Show answer
(c)
Q3Multiple choice
Figure 8.2 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 WIND, STORM AND CYCLONE 43 the straw rises up as soon as air is blown over its open end. Which one of the following best explains the reason for rise in level of the drink? Fig. 8.2
This question refers to a figure in the original PDF.
- (a)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)Blowing of air warms up the air inside the straw.
- (d)Blowing of air increases the pressure on the surface of soft drink in the bottle.
Show answer
(a) Blowing of air decreases pressure over the opening of the straw.
Q4Multiple choice
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)
Show answer
(d) (iv)
Q5Multiple choice
Which of the following place is most likely to be affected by a cyclone?
- (a)Mumbai
- (b)Puri
- (c)Goa
- (d)Porbandar
Show answer
(b) Puri
Q6Multiple choice
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.
Show answer
(b) get pushed outside the room.
Q7Very short answer
Why is Chandigarh unlikely to be affected by a cyclone?
Show answer
As it is not near to the sea/ocean.
Q8Very short answer
Name the ocean which is mainly responsible to bring rain bearing monsoon winds to Kerala coast in June every year?
Show answer
Indian Ocean
Q9Multiple choice
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.
Show answer
(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.
Q10Multiple choice
State whether the following statements are True or False:
- (i)If wind flows from land to the ocean, then it is daytime.
- (ii)A very high pressure system, with very high speed wind surrounding it forms a cyclone.
- (iii)The coast line of India is not vulnerable to cyclones.
- (iv)Warm air is lighter than cool air.
Show answer
(i) If wind flows from land to the ocean, then it is daytime.
(ii) A very high pressure system, with very high speed wind surrounding it forms a cyclone.
(iii) The coast line of India is not vulnerable to cyclones.
(iv) Warm air is lighter than cool air.
Q11Very short answer
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?
Show answer
B’s exhaust fan will expel the hot air more effectively because hot air rises up and her fan is at greater height than A’s.
Q12Very short answer
Why is it advisable not to shut all the doors and windows during a storm?
Show answer
To avoid the roof getting blown away due to the low pressure created by heavy wind.
Q13Very short answer
A flat in Mumbai with a balcony facing the sea has some clothes hung on a clothes line in the balcony. Towards which direction the clothes will be blown in the afternoon? Explain. WIND, STORM AND CYCLONE 45
Show answer
The clothes will be blown towards the house due to sea breeze blowing towards the land.
Q14Very short answer
Figure 8.3 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. Fig 8.3
This question refers to a figure in the original PDF.
Show answer
B as the wind is blowing from the sea to the land.
Q15Very short answer
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?
Show answer
Midnight. SHORT ANSWER QUESTIONS
Q16Match the following
Match Column I with Column II. There can be more than one match.
Show answer
(a) (ii) and (iv) (b) (i) and (iii) ANSWERS 115
Q17Short answer
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.
Show answer
The air inside the bottle contracts due to low temperature hence the bottle collapses due to the outside pressure.
Q18Short answer
When strong/high speed wind blows, an umbrella held upright at times gets upturned. Explain the reason.
Show answer
High speed wind passing over the umbrella creates low pressure. Therefore the umbrella upturns.
Q19Short answer
Suggest some precautions to be taken to prevent the roof of a tin sheet from flying away during a fierce wind storm.
Show answer
(i) Put heavy stones on it. (ii) Screw it tight. LONG ANSWER QUESTIONS
Q20Long answer
Describe an activity to demonstrate that warm air is lighter than cool air.
Show answer
Activity 8.6, Science Textbook, Class VII, NCERT or students may design any other activity and the teacher may verify the validity of the same.
Q21Long answer
The picture in Figure 8.4 shows tree line along the sea coast on an island near the equator. As shown, the tree tops are permanently bent in one direction. Are the trees bent towards the sea or away from it? Explain. Fig. 8.4
This question refers to a figure in the original PDF.
Show answer
In the day time wind blows from sea to land. This sea breeze makes the trees to bend towards the land.
Q22Long answer
Identify the names of six natural phenomena from the following word diagram given as Figure 8.5. Fig. 8.5
This question refers to a figure in the original PDF.