Test: Class 10 General Science NCERT Based - 3


25 Questions MCQ Test Science & Technology for UPSC CSE | Test: Class 10 General Science NCERT Based - 3


Description
This mock test of Test: Class 10 General Science NCERT Based - 3 for UPSC helps you for every UPSC entrance exam. This contains 25 Multiple Choice Questions for UPSC Test: Class 10 General Science NCERT Based - 3 (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Class 10 General Science NCERT Based - 3 quiz give you a good mix of easy questions and tough questions. UPSC students definitely take this Test: Class 10 General Science NCERT Based - 3 exercise for a better result in the exam. You can find other Test: Class 10 General Science NCERT Based - 3 extra questions, long questions & short questions for UPSC on EduRev as well by searching above.
QUESTION: 1

Consider the following:

1. Menstruation takes place when the egg is not fertilized.

2. HIV gets transmitted by eating with an infected person.

Which of the statements given above is/are incorrect?

Solution:
  • Menstruation is a periodic cycle that recurs every month and lasts for about two to eight days.

  • When egg does not gets fertilized, the thin lining of uterus which nourishes the embryo in event of fertilization, breakdowns and comes out of vagina as blood and mucous HIV is a Sexually Transmitted Disease which by mere contact (activities such as playing or eating) with infected person does not get transferred.

QUESTION: 2

Consider the following statements:

1. The number of successful variations in second generation is maximised by sexual reproduction than by asexual mode of reproduction.

2. Dominant and Recessive traits get expressed in sexual reproduction.

Which of the statements given above is/are correct?

Solution:
  • In asexual reproduction, if one bacterium divides, and then the resultant two bacteria divide again, the four individual bacteria generated would be very similar. There would be only very minor differences between them, generated due to small inaccuracies in DNA copying.

  • However, if sexual reproduction is involved, greater diversity will be generated, and the second generation will have differences that they inherit from the first generation, as well as newly created differences. Variations generated during birth can be hereditary. Due to these differences, survival of the organism can increase.

QUESTION: 3

Regarding sex determination, consider the following statements:

1. Sex is the determined by temperature in some species.

2. Sex is not genetically determined in snails.

3. The sex of human children is determined by which chromosome they inherit from their father.

Which of the statements given above is/are correct?

Solution:
  • Some species rely entirely on environmental cues. Thus, in some animals, the temperature at which fertilised eggs are kept determines whether the animals developing in the eggs will be male or female.

  • In other animals, such as snails, individuals can change sex, indicating that sex is not genetically determined. . In human beings, the sex of the individual is largely genetically determined.

  • Most human chromosomes have a maternal and a paternal copy, and we have 22 such pairs. But one pair, called the sex chromosomes, is different in men and women. So women are XX, while men are XY.

  • Thus, the sex of the children will be determined by what they inherit from their father. A child who inherits an X chromosome from her father will be a girl, and one who inherits a Y chromosome from him will be a boy.

QUESTION: 4

Which of the following places, witnesses the emergence of a modern human species?

Solution: The earliest members of human species, Homo sapiens, arose in Africa, moved across continents and developed into distinct races.

QUESTION: 5

Speciation is a process that leads to:

Solution:
  • Speciation is defined as the formation of new species from an existing species, either by evolution or by genetic modification.

  • A species is a group of organisms with similar characteristics and can interbreed to give a fertile offspring. Speciation is an evolutionary process of the formation of new and distinct species.

  • The new species get reproductively isolated from the previous species i.e., the new species can’t reproduce with the old species.

QUESTION: 6

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. Which of the following effects given below, defines the statement?

Solution: 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 the diffraction of light.

QUESTION: 7

Regarding the properties of the image formed by a plane mirror, consider the following statements:

1. Virtual and Erect images are formed by the Plane Mirror.

2. The size of the image is smaller to that of the object.

Which of the statements given above is/are correct?

Solution: The properties of the image formed by a plane mirror are

1. Image formed by a plane mirror is always virtual and erect.

2. The size of the image is equal to that of the object.

3. The image formed is as far behind the mirror as the object is in front of it.

4. The image formed is laterally inverted.

QUESTION: 8

Regarding the lens, consider the following statements:

1. A transparent material bound by two surfaces, of which one or both surfaces are spherical, forms a lens.

2. A lens, either a convex lens or a concave lens, has two spherical surfaces.

Which of the statements given above is/are correct?

Solution:
  • A transparent material bound by two surfaces, of which one or both surfaces are spherical, forms a lens. This means that a lens is bound by at least one spherical surface. In such lenses, the other surface would be plane. A lens may have two spherical surfaces, bulging outwards. Such a lens is called a double convex lens. It is simply called a convex lens. It is thicker at the middle as compared to the edges.

  • Similarly, a double concave lens is bounded by two spherical surfaces, curved inwards. It is thicker at the edges than at the middle. A double concave lens is simply called a concave lens.A lens, either a convex lens or a concave lens, has two spherical surfaces. Each of these surfaces forms a part of a sphere.

QUESTION: 9

Which of the following uses a concave mirror?

1. Torches

2. Vehicles headlights

3. Dentists to see larger images of the patient's teeth.

4. Shaving mirror

Select the correct answer using the code given below:

Solution:
  • Concave mirrors are commonly used in torches, searchlights and vehicles headlights to get powerful parallel beams of light as these mirrors possess the ability to focus parallel rays of light to a point, produce a large size image.

  • They are often used as shaving mirrors to see a larger image of the face The dentists use concave mirrors to see large images of the teeth of patients.Large concave mirrors are used to concentrate sunlight to produce heat in solar furnaces.

QUESTION: 10

Light travels the fastest in which of the following mediums?

Solution: Light propagates with different speeds in different media. Light travels the fastest in vacuum with the highest speed of 3×108 m s–1. Vacuum is free space and there are no obstacles to slow down light as the refractive index of vacuum is very low. In air, the speed of light is only marginally less, compared to that in vacuum. It reduces considerably in glass or water.

QUESTION: 11

Regarding the human eye, consider the following statements:

1. Light enters the eye through the cornea.

2. The pupil controls the amount of light entering the eye.

3. An inverted real image of the object is formed on the retina.

Which of the statements given above is/are correct?

Solution:
  • Light enters the eye, through a thin membrane called cornea. Cornea forms a transparent bulge on the front surface of the eyeball.

  • Pupil is a pigmented layer of tissues that makes up the colored portion of the eye. Its primary function is to control the amount of light entering in the eye.

  • The eye lens forms an inverted real image of the object on the retina. The retina is a delicate membrane having an enormous number of light-sensitive cells.

QUESTION: 12

Regarding the myopia, consider the following statements:

1. In a myopic eye, the image of a distant object gets formed behind the retina.

2. Myopia is caused by shortening of eyeballs.

Which of the statements given above is/are correct?

Solution: Myopia is also known as nearsightedness. A person with myopia can see nearby objects clearly but cannot see distant objects distinctly.

Myopia is caused by two reasons:

1. Excessive curvature of eye lens.

2. Elongation of eyeball. A person with this defect has the far point nearer than infinity. Such a person may see clearly upto a distance of a few metres.In a myopic eye, the image of a distant object is formed in front of the retina and not at the retina itself.

QUESTION: 13

Regarding the hypermetropia, consider the following statements:

1. A person with hypermetropia can see distant objects clearly.

2. Image is formed behind the retina.

3. Convex lens is used to correct this defect.

Which of the statements given above is/are correct?

Solution:
  • Hypermetropia is also known as farsightedness. A person with hypermetropia can see distant objects clearly but cannot see nearby objects distinctly. The near point, for the person, is farther away from the normal near point (25 cm).

  • Such a person has to keep a reading material much beyond 25 cm from the eye for comfortable reading. This is because the light rays from a closeby object are focussed at a point behind the retina.

  • This defect can be corrected by using a convex lens of appropriate power. Eye-glasses with converging lenses provide the additional focussing power required for forming the image on the retina.

QUESTION: 14

Which of the following parts of eyes is transplanted during eye donation?

Solution: Corneal blindness can be cured through corneal transplantation of donated eyes. Eye donors can belong to any age group or sex. People who use spectacles, or those operated for cataract, can still donate the eyes. People who are diabetic, have hypertension, asthma patients and those without communicable diseases can also donate eyes.

QUESTION: 15

Which of the following is the correct cause of the twinkling of stars?

Solution:
  • The twinkling of a star is due to atmospheric refraction. The starlight, on entering the earth’s atmosphere, undergoes refraction continuously, before it reaches the earth. The atmospheric refraction occurs in a medium of gradually changing refractive index.

  • Since the atmosphere bends starlight towards the normal, the apparent position of the star is slightly different from its actual position. The star appears slightly higher (above) than its actual position when viewed near the horizon.

  • Further, this apparent position of the star is not stationary, but keeps on changing slightly. Since the stars are very distant, they approximate point-sized sources of light.

  • As the path of rays of light coming from the star goes on varying slightly, the apparent position of the star fluctuates and the amount of starlight entering the eye flickers – the star sometimes appears brighter, and at some other time, fainter, which gives the twinkling effect.

QUESTION: 16

Consider the following pairs:

1. SI unit of electric charge – Ampere (A)

2. SI unit of electric current – Coulomb (C)

3. Instrument for measuring electric current in a circuit – Ammeter

Which of the pairs given above is/are correctly matched?

Solution:
  • The SI unit of electric charge is coulomb (C), which is equivalent to the charge contained in nearly 6 × 1018 electrons.

  • The electric current is expressed by a unit called ampere (A). One ampere is constituted by the flow of one coulomb of charge in a second, that is, 1 A = 1 C/1 s. An instrument called ammeter measures electric current in a circuit. To measure the current in a circuit, it is connected in series in a circuit.

QUESTION: 17

Which of the following laws states that- the electric current flowing through a metallic wire is directly proportional to the potential difference V, across its ends, provided its temperature remains the same?

Solution:
  • In 1827, a German physicist Georg Simon Ohm (1787–1854) found out the relationship between the current I, flowing in a metallic wire and the potential difference across its terminals.

  • He stated that the electric current flowing through a metallic wire is directly proportional to the potential difference V, across its ends provided its temperature remains the same. This is called Ohm’s law.

QUESTION: 18

Resistance of a conductor depends upon which of the following factors:

1. On its length

2. On its area of cross-section

3. On the nature of its material

Which of the statements given above is/are correct?

Solution: On applying Ohm’s law, we observe that the resistance of a conductor depends (i) on its length, (ii) on its area of cross-section, and (iii) on the nature of its material. Precise measurements have shown that resistance of a uniform metallic conductor is directly proportional to its length (l) and inversely proportional to the area of cross-section (A).

QUESTION: 19

Which of the following inorganic gases are filled in bulbs?

1. Nitrogen

2. Helium

3. Argon

4. Hydrogen

Solution:
  • The bulbs are usually filled with chemically inactive gas - nitrogen/ argon, to prolong the life of filament. The closed glass chamber of a bulb contains an inactive gas Argon or Nitrogen.

  • The glass chamber cannot be filled with air as the presence of oxygen will cause the filament to burn and a vacuum will evaporate the filament. Inert gases like argon do not react and will maintain a particular pressure preventing filament from burning.

QUESTION: 20

Which one of the following describes the direction of an electric current?

Solution: A stream of electrons moving through a conductor constitutes an electric current.

Conventionally, the direction of current is taken opposite to the direction of flow of electrons.

QUESTION: 21

Which of the following scientists had first observed the magnetic effect of electric current?

Solution:
  • Hans Christian Oersted, one of the leading scientists of the 19th century, played a crucial role in understanding electromagnetism. In 1820 he accidentally discovered that a compass needle got deflected when an electric current passed through a metallic wire placed nearby.

  • Through this observation Oersted showed that electricity and magnetism are related phenomena. His research later created technologies such as radio, television and fiber optics. The unit of magnetic field strength has been named as Oersted in his honor.

QUESTION: 22

If the current through the wire increases, the magnitude of the magnetic field produced at a given point:

Solution: The current flowing through a conductor is directly proportional to magnetic field. As the electric current through the wire increases, the magnitude of the magnetic field produced at a given point increases.

QUESTION: 23

Consider the following statements:

1. The Direct Current does not change its direction with time.

2. A current, which changes direction after equal intervals of time, is called an alternating current.

3. Alternating current is used in transmissions over long distances.

Which of the statements given above is/are correct?

Solution:
  • A current, which changes direction after equal intervals of time, is called an alternating current while direct current (DC) does not change its direction with time. The difference between the direct and alternating currents is that the direct current always flows in one direction, whereas the alternating current reverses its direction periodically.

  • Most power stations constructed these days produce alternating current (AC). In India, the AC changes direction after every 1/100 second, that is, the frequency of AC is 50 Hz. An important advantage of AC over DC is that electric power can be transmitted over long distances without much loss of energy.

QUESTION: 24

Which of the following statements is the phenomenon of electromagnetic induction?

Solution:
  • The phenomenon of electromagnetic induction is the production of induced current in a coil placed in a region where the magnetic field changes with time. The magnetic field may change due to a relative motion between the coil and a magnet placed near to the coil.

  • If the coil is placed near to a current carrying conductor, the magnetic field may change either due to a change in the current through the conductor or due to the relative motion between the coil and conductor.

QUESTION: 25

The magnetic field?

1. Brain

2. Kidney

3. Heart

4. Liver

Solution:
  • Two main organs in the human body where the magnetic field gets produced are the heart and the brain. The magnetic field inside the body forms the basis of obtaining the images of different body parts.

  • This is done using a technique called Magnetic Resonance Imaging (MRI). Analysis of these images helps in medical diagnosis. Magnetism has thus also got an important application in medicine.