The presence of certain minerals is essential in water, however, if found in excess they can be harmful to our body. In this context, which of the following statements are correct?
1. Deficiency of fluoride in drinking water causes diseases such as tooth decay.
2. Excessive sulphate in drinking water causes laxative effect.
3. Excess lead in drinking water can cause disease such as ‘blue baby’ syndrome.
Select the correct answer using the code given below.
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Some countries now use alcohol as an additive in petrol. In context of this, consider the following statements:
1. Addition of alcohol increases the burning efficiency of petrol and reduces knocking.
2. Petrol added with small quantities of alcohol becomes more stable and doesn’t become too hot in warm areas or too cold in freezing temperatures.
3. Alcohol is a cleaner fuel which gives rise to only carbon dioxide and water on burning in sufficient oxygen.
Which of the statements given above is the correct reason for using alcohol as an additive in petrol?
Consider the following statements about the ‘fuel obtained from plastic waste’:
1. It has low octane rating.
2. Lead content is absent in it.
3. It is known as green fuel.
Which of the statements given above is/are correct?
With reference to ‘Magnetic Field’, consider the following statements:
1. The magnetic field produced by a current-carrying wire at a given point depends directly on the current passing through it.
2. The magnetic field inside a long straight solenoid-carrying current is zero.
Which of the statement(s) given above is/are correct?
Which among the following method(s) is/are used by pests to attack crops sown in the field?
1. They attack the root of the plant.
2. They bore into stem and fruits of the plant.
3. They suck water from various parts of the plant.
Select the correct answer using the code given below:
Consider the following statements:
1.
Water vapour present in the atmosphere is formed due to which of the following factors?
1. Heating of water bodies.
2. Activities of living organisms.
3. Weathering of rocks.
4. Photosynthesis.
Select the correct answer using the code given below:
In context of Air pollution in India, consider the following statements:
1. Presence of high levels of pollutants in air causes visibility to be lowered.
2. Formation of smog is a visible indication of air pollution.
3. Oxides of nitrogen and sulphur dissolve in rain to give rise to acid rain.
Which of the statement(s) given above is/are correct?
Consider the following statements about the ‘properties of ethanol’:
1. Ethanol is insoluble in water.
2. Consumption of small quantities of dilute ethanol causes drunkenness.
3. Ethanol can be blended with diesel.
4. Ethanol is used as a solvent in many medicines.
Which of the statements given above are correct?
Consider the following statements about Carbon dioxide (CO2):
1. Volcanic eruptions are a natural source of Carbon dioxide in the atmosphere.
2. Carbon dioxide is confined only to the tropospheric layer of the atmosphere.
3. Excess of Carbon dioxide in the air is removed by green plants by respiration.
Which of the statements given above is/are correct?
Read the following statements carefully in the context of ‘particulate pollutants’?
1. Smoke particulates consist of gaseous or mixture of gaseous and liquid particles formed during combustion of organic matter.
2. Dust is composed of fine solid particles produced during crushing, grinding and attribution of solid materials.
3. Mists are produced by particles of spray liquids and by condensation of vapours in air.
4. Fumes are generally obtained by the condensation of vapours during sublimation, and boiling.
Which of the statements given above are correct?