INSIGHT UPSC QUIZ

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:

 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?

The most common nutrients causing eutrophication are:

 Consider the following statements with reference to the ‘magnetic field’ of a bar magnet:

1. Magnetic field is a quantity that has both direction and magnitude. 

2. Inside the magnet, the direction of field lines is from its south pole to north pole.

3. Magnetic field-lines of two different magnets can intersect each other.

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

Consider the following statements: 

1. The motion of the moon around the earth is due to the centrifugal force. 

2. The moon rotates around its axis due to the gravitational pull of the earth. 

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

With reference to organic farming practices prevalent in India, consider the following statements:

1. Which of the following statement(s) in the context of ‘Human Eye’ is/are NOT correct?

1. Most of the refraction of the light rays entering the eye occurs at the outer surface of the crystalline lens.

2. Iris is a dark muscular diaphragm that controls the size of the pupil. 

3. Pupil regulates and controls the amount of light entering the eye. 

4. Retina is a delicate membrane having enormous number of light-sensitive cells.

Select the correct answer using codes given below:

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?

Consider the following statements about pesticide residue in our food chain:

1. It is introduced in the food chain by aquatic plants and animals.

2. These chemicals get accumulated progressively at each trophic level. 

3. Human body accumulates minimum concentration of these chemicals.

Select the correct answer using the code given below:

 Consider the following statements: