Advertisements
Advertisements
प्रश्न
Water polluted by various human activities causes a number of water borne diseases. Which of the following is not a water borne disease?
विकल्प
Cholera
Typhoid
Asthma
Dysentry
Advertisements
उत्तर
Asthma
Explanation:
Asthma is an air borne respiratory disease. It is caused due to an allergy to dust, pollen grains or any other allergen present in the air.
APPEARS IN
संबंधित प्रश्न
Name the four main sources of water.
Name the two gases from which water is formed. What is the chemical composition of these two gases in water ?
Freezing mixture contains ............. and .............
Give one word for the following statement:
A mixture of common salt and ice .
Describe the water-cycle in nature.
Explain how the peculiar variation of density of water with temperature can protect marine-life.
Identify A, B, C and D; first one is done for you.
Explain why:
If distilled water is kept in a sealed bottle for a long time, it leaves etchings on the surface of the glass.
Explain why:
Table salts become sticky on exposure to humid air during the rainy season.
Name the solute, solvent & solution in the statement – ‘sodium chloride dissolves in water to give sodium chloride solution’. Define each of the terms in italics.
Name one substance which is ‘deliquescent’.
Explain the following observation:
Washing-soda become coated with a white powder when left exposed to the atmosphere.
Match the terms in List I with the correct answers in List II.
| List I | List II |
| 1. Solubility in a given solvent decreases with an increase in temperature. | A: Na2SO4.10H2O |
| 2. A white efflorescent crystal | B: NaOH |
| 3. A hygroscopic dehydrating agent | C: Ca(HCO3)2 |
| 4. A deliquescent alkali | D: conc. H2SO4 |
| 5. A substance present in temporary hard water | E: CaSO4 |
Suggest some ideas to save rainwater in your school.
In the coastal areas, wind current moves from the sea towards the land during the day; but during the night it moves from land to the sea. Discuss the reason.
From where do the following usually get water? In which form is water present in them?
Animals
Animal waste, oil and urea are some of the organic impurities present in sewage. Name two more organic impurities present in sewage.
Wells are fed by ______.
Look at the figure.
Write down activities shown in this figure in which water is being used.
