Questions & answers for Chapter 15 Air around us

Chapter 15 Air around us Questions and Answers for class 6 Science

Find below Important MCQ-based objective questions for Chapter 15 Air around us prepared for CBSE students. All the syllabus of Class 6 Science Chapter 15 Air around us is covered with questions and answers. Each question is explained with a detailed solution. The entire syllabus of Chapter 15 Air around us is covered in the following worksheet for class 6 science. For more worksheets for class 6 science click on the link and do check out NCERT solutions for class 6 science. 

Find below Class 6 Science Chapter 15 Air around us Questions & Answer

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Class 6 Science Chapter 15 Air around us Questions & Answer Set-1

Science - MCQ on Air Around Us

Class VI

Q.1.The blanket of air that surrounds the earth is called

a. Hydrosphere.

b. Lithosphere.

c. Atmosphere.

d. Biosphere.

Answer:

(c)

Explanation- Atmosphere is the envelope of air which surrounds the earth. It extends upto about 1000 km above the surface of the earth.

Q.2.The gas used in fire extinguisher is

a. oxygen.

b. carbon dioxide.

c. nitrogen.

d. hydrogen.

Answer:

(b)

Explanation- Carbon dioxide is heavier than oxygen. So, it covers the fire like a blanket. The supply of oxygen to the fuel stops and the fire is controlled.

Q.3. Air is a/an

a. compound.

b. element.

c. metal.

d. mixture.

Answer:

(d)

Explanation- Air is a mixture of gases mainly nitrogen (78%) and oxygen (21%). It also consists of argon, carbon dioxide (0.03%), small amount of other gases and water vapour.

Q.4. Contamination of air by unwanted and harmful substances is known as

a. noise pollution.

b. air pollution.

c. water pollution.

d. soil pollution.

Answer:

(b)

Explanation- Air pollution is the contamination of air by impurities which adversely affect the living organisms and non-living components.

Q. 5.The balance of oxygen and carbon dioxide in atmosphere is maintained through

a. photosynthesis in plants and respiration in plants and animals.

b. transpiration in plants.

c. photosynthesis in plants.

d. respiration in animals.

Answer:

(a)

Explanation-Plants consume carbon dioxide and produce oxygen during photosynthesis. They consume oxygen for respiration but release more of it in photosynthesis. Animals consume oxygen and produce carbon dioxide in respiration. Thus, plants and animals are interdependent on each other for exchange of oxygen and carbon dioxide and they balance oxygen and carbon dioxide in atmosphere.

Q. 6.The movement of a glider is due to

a. water.

b. solar energy.

c. air.

d. fuel.

Answer:

(c)

Explanation-A glider is a special type of aircraft supported only by the moving action of air against its surfaces.

Q. 7.The gas which protects us from ultraviolet rays is

a. carbon monoxide.

b. nitrogen.

c. oxygen.

d. ozone.

Answer:

(d)

Explanation- Ozone is a gas which forms a layer in the atmosphere. It protects us from harmful ultraviolet rays of the sun.

Q. 8.The layer of the earth maintaining the right temperature for life to exist is

a. Atmosphere.

b. Lithosphere.

c. Hydrosphere.

d. Biosphere.

Answer:

(a)

Explanation- Atmosphere helps to maintainthe right temperature on the earth. It sends back or absorbs a part of sunlight and heat that falls on the upper parts of it.

Q. 9.The percentage of carbon dioxide in air is

a. 0.01%.

b. 0.02%.

c. 0.03%.

d. 0.04%.

Answer:

(c)

Explanation- Air contains 0.03% carbon dioxide.

Q.10.Earthworms come out from the burrows during

a. winter.

b. summer.

c. autumn.

d. heavy rains.

Answer:

(d)

Explanation-The animals that live in the soil form burrows in deep soil. These burrows make spaces available for air to move in and out of the soil. Due to heavy rains, water fills in the air spaces present in the soil and the animals have to come out for respiration.

Q.11.The gas used by green plants to produce starch is

a. carbon monoxide.

b. carbon dioxide.

c. oxygen.

d. argon.

Answer:

(b)

Explanation- The green plants prepare their food (starch) from carbon dioxide and water using sun-light by photosynthesis. Oxygen is released in this process.

Q.12.Dust particles cannot go into the respiratory system as they are prevented by

a. lungs.

b. trachea.

c. alveoli.

d. fine hair and mucus present in the nose.

Answer:

(d)

Explanation- At the time of breathing, we inhale air through our nostrils. These nostrils containfine hair and mucus which protect us from the dust particles present in air.

Class 6 Science Chapter 15 Air around us Questions & Answer Set-2

Q.13.Mountaineers carry oxygen cylinder with them because air is

a. dense at height.

b. thin at height.

c. polluted at height.

d. vanished at height.

Answer:

(b)

Explanation- At height, air is thin. So, mountaineers inhale oxygen from the cylinders.

Q.14.The transparent glass of windows, sometimes appears hazy because air contains

a. water vapour and dust particles.

b. nitrogen.

c. carbon dioxide.

d. oxygen.

Answer:

(a)

Explanation- The water vapours present in air condense to water droplets. These droplets along with dust particles form mist. Hence, if the transparent glass of windows is not wiped off regularly then it appears hazy.

Q.15. When somebody is caught fire, then it is advised to wrap a

a. cotton sheet.

b. silk sheet.

c. woolen blanket.

d. synthetic blanket.

Answer:

(c)

Explanation- Woolen blanket should be used to wrap a person caught fire because wool does not burn easily and stops the supply of air (oxygen), so that the fire can be extinguished.