Chapter 28: STARS


The moon completes one rotation around its axis in 29 days and same time it take to complete one revolution around the earth. Hence, we never see the other side of the moon. Pole star doesn’t move from its position as it’s located on earth’s axis.

Mercury is smallest planet and closest to the sun. It has no satellites. Venus [Earths twin] is closest to the earth and rotates east to west. Saturn is less dense than water. Uranus has a highly tilted axis; it appears to be rolling on its side. It also rotates from east to west. First four planets are rocky with few satellites or no. But outer planets are gaseous and with many satellites.

Asteroids are found between mars and jupiter.largest asteroid is cerus. Comets have an elliptical orbit around the sun and have a long period of revolution. Their tail is always away from the sun. Meteors are objects that enter the earth’s atmosphere, usually they burn in the atmosphere but sometimes they fall on the earth. This fallen body is called meteorite. Atmosphere regulates temperature of the planet by allowing it to cool slowly in day time and during night time trapping the heat and preventing it from escaping.

Ozone layer absorbs the harmful UV-B radiations of the sun. But due to CFC’s it is thinning and this leads to a hole in the ozone layer above Antarctica. Ozone [O3] is the product of UV radiations. UV rays split the O2 molecule into free atoms which combine with the O2 molecule to form ozone molecule.  Depletion of ozone layer above Antarctica is seen and is called ozone hole. This is due to formation of polar stratospheric clouds in summer which cause depletion. In winter chlorine sinks are present which prevent ozone depletion.

Greenhouse effect is seen when the long wave radiation of the earth is absorbed by the greenhouse gases causing heating of the atmosphere.

Q.‘Project Loon’, sometimes seen in the news, is related to (UPSC CSAT 2016)

  1. waste management technology

  2. wireless communication technology

  3. solar power production technology

  4. water conservation technology

Ans . B

Q.With reference to ‘Li-Fi’, recently in the news, which of the following statements is/are correct?
1. It uses light as the medium for high-speed data transmission.
2. It is a wireless technology and is several times faster than ‘WiFi’.
Select the correct answer using the code given below. (UPSC CSAT 2016)

  1. 1 only

  2. 2 only

  3. Both 1 and 2

  4. Neither 1 nor 2

Ans . C

  1. Li-fi gives data transfer rate of 10 gigabytes per second

  2. Li-Fi device circulates data via LEDs that emit an intermittent flicker at a speed imperceptible to the human eye

Q.What is ‘Greased Lightning-10 (GL-10)’, recently in the news? (UPSC CSAT 2016)

  1. Electric plane tested by NASA

  2. Solar-powered two-seater aircraft designed by Japan

  3. Space observatory launched by China

  4. Reusable rocket designed by ISRO

Ans . A

  1. NASA has developed and successfully flight tested a battery-powered plane with 10 engines that can take off and land like a helicopter and fly efficiently like an aircraft

Q.With reference to `Astrosat’, the astronomical observatory launched by India, which of the following statements is/are correct?
1. Other than USA and Russia, India is the only country to have launched a similar observatory into space.
2. Astrosat is a 2000 kg satellite placed in an orbit at 1650 km above the surface of the Earth.
Select the correct answer using the code given below. (UPSC CSAT 2016)

  1. 1 only

  2. 2 only

  3. Both 1 and 2

  4. Neither 1 nor 2

Ans . D

  1. Astosat weighs 1513 kgs.

  2. USA, Russia, Japan and Europe have such space observatories.

Q.India is an important member of the ‘International Thermonuclear Experimental Reactor’. If this experiment succeeds, what is the immediate advantage for India? (UPSC CSAT 2016)

  1. It can use thorium in place of uranium for power generation

  2. It can attain a global role in satellite navigation

  3. It can drastically improve the efficiency of its fission reactors in power generation

  4. It can build fusion reactors for power generation

Ans . D

Q.Consider the following statements:
The Mangalyaan launched by ISRO
1. is also called the Mars Orbiter Mission
2. made India the second country to have a spacecraft orbit the Mars after USA
3. made India the only country to be successful in making its spacecraft orbit the Mars in its very first attempt
Which of the statements given above is/are correct? (UPSC CSAT 2016)

  1. 1 only

  2. 2 and 3 only

  3. 1 and 3 only

  4. 1, 2 and 3

Ans . C

Q.In the context of the developments in Bioinformatics, the term ‘transcriptome’, sometimes seen in the news, refers to (UPSC CSAT 2016)

  1. a range of enzymes used in genome editing

  2. the full range of mRNA molecules expressed by an organism

  3. the description of the mechanism of gene expression

  4. a mechanism of genetic mutations taking place in cells

Ans . B

Q.Mission Indradhanush’ launched by the Government of India pertains to (UPSC CSAT 2016)

  1. immunization of children and pregnant women

  2. construction of smart cities across the country

  3. India’s own search for the Earth-like planets in outer space

  4. New Educational Policy

Ans . B

Q.With reference to pre-packaged items in India, it is mandatory to the manufacturer to put which of the following information on the main label, as per the Food Safety and Standards (Packaging and Labelling) Regulations, 2011?
1. List of ingredients including additives
2. Nutrition information
3. Recommendations, if any, made by the medical profession about the possibility of any allergic reactions
4. Vegetarian/non-vegetarian
Select the correct answer using the code given below. (UPSC CSAT 2016)

  1. 1, 2 and 3

  2. 2, 3 and 4

  3. 1, 2 and 4

  4. 1 and 4 only

Ans . C

  1. Labels have to contains 1, 2 and 4

Q.Which of the following statements is/are correct? Viruses can infect
1. bacteria
2. fungi
3. plants
Select the correct answer using the code given below (UPSC CSAT 2016)

  1. 1 and 2 only

  2. 3 only

  3. 1 and 3 only

  4. 1, 2 and 3

Ans .

  1. viruses are classified mainly into the following four types. Plant viruses including algal viruses-RNA/DNA

  2. Animal viruses including human viruses-DNA/RNA

  3. Fungal viruses(Mycoviruses)-ds RNA

  4. .Bacterial viruses (Bacteriophages) including cyanophages

Q.The term ‘Goldilocks Zone’ is often seen in the news in the context of (UPSC CSAT 2015)

  • the limits of habitable zone above the surface of the Earth

  • regions inside the Earth-like planets in outer space

  • search for the Earth-like planets in outer space

  • search for meteorites containing precious metals

Ans . C

  1. In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone (Goldilocks Zone), is the region around a star within which planetary-mass objects with sufficient atmospheric pressure can support liquid water at their surfaces.

  2. Researchers are finding that life can thrive in some unexpected places.


Score more than 80% marks and move ahead else stay back and read again!