Model Practice Test- 4


25 Questions MCQ Test Science & Technology for UPSC CSE | Model Practice Test- 4


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This mock test of Model Practice Test- 4 for UPSC helps you for every UPSC entrance exam. This contains 25 Multiple Choice Questions for UPSC Model Practice Test- 4 (mcq) to study with solutions a complete question bank. The solved questions answers in this Model Practice Test- 4 quiz give you a good mix of easy questions and tough questions. UPSC students definitely take this Model Practice Test- 4 exercise for a better result in the exam. You can find other Model Practice Test- 4 extra questions, long questions & short questions for UPSC on EduRev as well by searching above.
QUESTION: 1

Human beings cannot hear ultrasonic sound waves because

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QUESTION: 2

High frequency ultrasonic waves can be used

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QUESTION: 3

If light from the white hot filament of an electric lamp is passed through hot sodium vapour, then the spectrum obtained from this

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QUESTION: 4

Electromagnetic waves radiated by an incandescent source mostly consists of

Solution:

The correct option is A.
IR is a type of electromagnetic radiation, a continuum of frequencies produced when atoms absorb and then release energy. From highest to lowest frequency, electromagnetic radiation includes gamma-rays, X-rays, ultraviolet radiation, visible light, infrared radiation, microwaves and radio waves.

QUESTION: 5

In the nuclear reactor, graphite is used so as to

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QUESTION: 6

Which of the following statements in correct?

  1. Galaxies generally contain between 106 and 1012 stars.
  2. Nebula is a cloud of gas and dust floating in space.
  3. Saros period is of 18 years and 11.3 days during which the Sun, Earth and Moon return to almost the same relative positions.
  4. Geodesy refers to the study of the shape and the gravitational field of the Earth upon data collected from artificial satellites.
Solution:

Correct option is B

The Sun belongs to a galaxy called the Milky Way. Astronomers estimate there are about 100 thousand million stars in the Milky Way alone. Outside that, there are millions upon millions of other galaxies also!

A nebula is a giant cloud of dust and gas in space. Some nebulae (more than one nebula) come from the gas and dust thrown out by the explosion of a dying star, such as a supernova. Other nebulae are regions where new stars are beginning to form. A nebula is a giant cloud of dust and gas in space.

The periodicity and recurrence of eclipses is governed by the Saros cycle, a period of approximately 6,585.3 days (18 years 11 days 8 hours). It was known to the Chaldeans as a period when lunar eclipses seem to repeat themselves, but the cycle is applicable to solar eclipses as well.

Geodesy is the science of accurately measuring and understanding the Earth's geometric shape, orientation in space, and gravity field. Today, geodesists use space-based tools like the Global Positioning System (GPS) to measure points on the Earth's surface.

QUESTION: 7

Which of the following statements is correct?

  1. Spicules are the eruptions occuring on the Sun’s surface due to the regular upwelling of supergranules.
  2. Internal disturbances in the Sun’s magnetic field manifest themselves as sunspots on the Sun’s surface.
  3. The temperature of the sunspot is 6000°C.
  4. The limit of mass beyond which a star will not become a red giant is called  the Chandrasekhar Limit.
Solution:

The correct option is C.
Solar measurements reveal that the average surface temperature of the sun is 6000° Celsius and that sunspots are about 1500° Celsius cooler than the area surrounding them (still very hot), and can last anywhere from a few hours to a few months.

QUESTION: 8

Which of the following statements is correct?

  1. After a supernova explosion, the remaining part of the star is called a neutron star.
  2. The terminator is the boundary between the day and night sides of the Moon.
  3. The Crater C operni cus has been ni ck -named “Monarch of the Moon” due to its impressive features.
  4. All matter falling into a Bl ack Hole will have about 70% of its mass converted into energy.
Solution:

D is the correct option. I, II and III are correct.
Statement IV is not correct as Accretion onto a black hole is the most efficient process for emitting energy from matter in the Universe, releasing up to 40% of the rest mass energy of the material falling in. 

QUESTION: 9

For a good health, humidity of a room should be about

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QUESTION: 10

Tape recorder records sound in the form of

Solution:

Magnetic field on the tape.  Explanation: A tape is coated with tiny magnetic particles. These particles get magnetized, when electric signal passes through them. Thus, a tape recorder records sound in the form of magnetic field on the tape.

QUESTION: 11

When angle of incidence in a denser medium is equal to critical angle, the angle of refraction is

Solution:

The correct option is Option C.

Qs shown in the fig angle of incidence in denser medium increases angle of refraction also increases. 
When angle of incidence equals the critical angle, the angle of refraction will be 90°. and if further increase in the incidence angle light undergoes reflection.
 

QUESTION: 12

Velocity of light increases in the order of

Solution:

velocity of light in diamond=124000km/s
velocity of light in glass =200000km/s
velocity of light in water =225000km/s

Hence increasing order is diamond; glass and water.

QUESTION: 13

Which is known as India’s contraceptive plant?

Solution:

Dioscorea deltoidea is known as India’s contraceptive plant. 
It is an endangered species belonging to family Dioscoreacea, It produce rhizomes or bulbils which is rich in sapogenin steroidal compounds. These compounds have immense medicinal, industrial and commercial importance. D. deltoidea is expectorant and sedative.
 

QUESTION: 14

Which is the main agent of food-borne disease in industrialized countries?

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QUESTION: 15

Which dal causes Lathyrism?

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QUESTION: 16

Since the widespread use of DDT, one of the following effects has been observed in birds:

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QUESTION: 17

Lie detector is an instrument used for

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QUESTION: 18

Electroencephalogram records changes in el ectric potential in the

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QUESTION: 19

Percentage of water in plant is

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QUESTION: 20

Which tissue gives mechanical support to parts of a plant?

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QUESTION: 21

Which is not a bone of the human leg?

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QUESTION: 22

Nucleic acids in organisms are rich in

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QUESTION: 23

Which mineral in the human body helps to maintain normal water balance?

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QUESTION: 24

The life span of human red corpuscles is

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QUESTION: 25

Which part of the plant transport water and dissolved minerals from the roots to the leaves?

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