INSIGHT UPSC QUIZ

 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 ‘rainbow’:

1. It is caused by dispersion of sunlight by tiny water droplets present in the atmosphere. 

2. A rainbow is always formed in a direction opposite to that of the Sun.

Which of the statements given above is/are correct?

With reference to the uses of ‘concave mirrors’, read the following statements carefully:

1. They are commonly used in vehicles headlights to get powerful parallel beams of light. 

2. They are often used as shaving mirrors to see a larger image of the face. 

3. They are fitted on the sides of the vehicle to have a wider field of view.

4. Large concave mirrors are used to concentrate sunlight to produce heat in solar furnaces.

Which of the statements given above is/are correct?

Which of the following phenomena are caused due to ‘atmospheric refraction’?

1. Flickering of objects seen through a turbulent stream of hot air rising above a fire.

2. The reddening of the sun at sunrise and the sunset.

3. The apparent flattening of the Sun’s disc at sunrise and sunset.

4. The Sun is visible to us about 2 minutes before the actual sunrise, and about 2 minutes after the actual sunset.

Select the correct answer using the code given below.

 Consider the following statements:

1.  Large air cavities are present underneath the skin of aquatic plants that help them in floating.

2. Chlorophyll is present underneath the skin of terrestrial plants and it helps them in manufacturing food.

Which of the statement(s) given above is/are NOT correct?

Read the following statements carefully and select the correct answer from codes given below:

1. Working of electric motors involves the electric effect of electric current.

2. Working of electric generators involves the magnetic effect of moving magnets. 

Which of the statement(s) given above is/are correct?

Desirable characteristics of a crop variety helps in easy adoption of that crop by the farmers. In this context, consider the following statements:

1. Incorporating desirable characters into crop varieties can be done through fertilisation.

2. Dwarfness is desired in cereals, so that less nutrients are consumed by these crops. 

3. Hybridisation refers to crossing between genetically similar plants.

Which of the statement(s) 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?

Read the following statements carefully and select the correct answer from codes given below:

1. The phenomenon of splitting of white light into its seven component colours by a prism is called dispersion.

2. While passing through a prism, the violet light bends the least while the red the most.

3. Isaac Newton was the first to use a glass prism to obtain the spectrum of sunlight.

Which of the statements given above is/are correct?

If an opaque object on the path of light becomes very small, light has a tendency to bend around it and not walk in a straight line. This effect is known as: