INSIGHT UPSC QUIZ

The twinkling of a star occurs due to atmospheric refraction of starlight. This twinkling phenomenon occurs only in stars and not in planets, it is because of which of the following reasons?

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:

 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: 

1. Cold-blooded animals do not have the capacity to regulate their body temperature. 

2. Amphibians are cold-blooded animals and reptiles are warm-blooded animals.

Which of the statements 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?

 Manure contains large quantities of organic matter and also supplies small quantities of nutrients to the soil. In this context, consider the following statements:

1. The organic matter in manure helps in improving the soil structure.

2. It increases the water holding capacity in sandy soils.

3. It causes water logging in clayey soils.

Select the correct answer using the code given below:

 In the context of nature of light, read the following statements carefully: 

1. Light does not travel in the same direction in all mediums. 

2. Light propagates with different speeds in different mediums. 

3. Light travels fastest in air with speed of 3×10⁸ m/s. 

4. Speed of light reduces considerably in glass or water.

Which of the statements given above is/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?

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

1. The B-lymphocytes in human body produce an army of proteins in response to pathogens into our blood to fight with them. 

2. The T-lymphocytes mediate cell-mediated immunity (CMI) which is responsible for the graft (transplanted body-part) rejection. 

Select the correct answer using the code given below.

Consider the following statements: 

1. The ‘danger’ signal lights are red in colour as the red is least scattered by fog or smoke.

2. The sky appears dark to passengers flying at very high altitudes because of scattering of light. 

Which of the statements given above is/are correct?