CBSE Class 10 Science NSO Olympiad MCQs with Answers Set D

Logical Reasoning

Question. Find the missing number, if a certain rule is followed in all the three figures.

A. 1
B. 2
C. 5
D. 6
Answer : B

Question. Select a figure from the options which will complete the pattern in Fig. (X).

Answer : A

Question. Find the correct mirror image of Fig. (X), if the mirror is placed vertically to the left.
3 C 0 9 M 6 P E 3 T E

Answer : B

Question. Study the following information carefully.
(i) A, B, C, D and E are five men sitting in a line facing to South – while M, N, O, P and Q are five ladies sitting in a second line parallel to the first line and are facing to North.
(ii) B who is just next to the left of D, is opposite to Q.
(iii) C and N are diagonally opposite to each other.
(iv) E is opposite to O who is just next right of M.
(v) P who is just to the left of Q, is opposite to D.
(vi) M is at one end of the line.
Who is sitting just opposite to N?
A. B
B. A
C. D
D. E
Answer : B

Question. There is a certain relationship between the figures (1) and (2). Establish the same relationship between the figures (3) and (4) by selecting a suitable figure from the options which will replace the (?) in figure (4).

Answer : D

Question. A word arrangement machine, when given an input line of words, rearranges them in a particular rule in each step. The following is an illustration of input and the steps of rearrangement.
Input : quick heat 51 82 39 war 91 green
Step I : green quick heat 51 82 39 war 91
Step II : green 39 quick heat 51 82 war 91
Step III : green 39 quick 51 heat 82 war 91
Step III is the last step of this input.
Which of the following is the last step of the given input?
Input : down 52 24 81 plank wood home 43.
A. V
B. VI
C. IV
D. VII
Answer : A

Question. If ‘–’ stands for ‘division’, ‘+’ for ‘multiplication’, ‘÷’ for ‘subtraction’ and ‘×’ for ‘addition’, then which of the following options is correct?
A. 6 + 20 – 12 ÷ 7 – 1 = 38
B. 6 – 20 ÷ 12 × 7 + 1 = 57
C. 6 + 20 – 12 ÷ 7 × 1 = 62
D. 6 ÷ 20 × 12 + 7 – 1 = 70
Answer : D

Question. In which of the following figures, Fig. (X) is exactly embedded as one of its part?

Answer : D

Question. How many pairs of letters are there in the word DIPLOMACY which have the same number of letters between them as in English alphabet ?
A. Three
B. Four
C. Five
D. Six
Answer : A

Question. Study the given figure carefully.
What is represented by the number 7?

A. Married doctors in the hospital
B. Doctors having clinics
C. Unmarried doctors having clinics
D. Married doctors having clinics
Answer : A

Science

Question. A particle moves on a one-dimensional path. If motion of the particle is described by x(t) = t₂ – 3t + 2, then which of the following statements is correct?
A. x(t) > 0 and a(t) > 0 for all t > 0
B. v(t) > 0 and a(t) > 0 for all t > 0
C. x(t) > 0 and v(t) > 0 for all t > 0
D. None of these
Answer : D

Question. Mr. Tiwari, who cannot see objects nearer than 1 m from his eyes, wants to read a book placed at a distance of 25 cm clearly. The nature and the power of lens required by Mr. Tiwari are
Nature of the lens        Power of the lens
A. Convex                          +5 D
B. Concave                       – 5 D
C. Convex                         + 3 D
D. Concave                       – 3 D
Answer : C

Question. Aditya weighing 50 kg runs along the rails with a velocity of 13.5 km h^–1 and jumps into a trolley of mass 1 quintal, standing on the rails. The velocity with which the trolley starts moving along the rails, is
A. 12.5 × 10² cm s^–1
B. 12.5 × 10^–2 dm s^–1
C. 12.5 × 10³ mm s^–1
D. 12.5 × 10^–1 m s^–1
Answer : D

Question. A bat produces ultrasound and audible sound at the same time. Which of the following statements is true?
A. Ultrasound travels faster than the audible sound.
B. Ultrasound and audible sound have the same frequency.
C. The wavelength of the ultrasound is longer than the wavelength of the audible sound.
D. Ultrasound and audible sound will reach the same distance at the same time.
Answer : D

Question. The given figure shows the motion of a planet around the sun in an elliptical orbit with the sun at the focus. The shaded areas A₁ and A₂ shown in figure are such that A₁ > A₂. If t₁ and t₂ represent the time taken by the planet to move from P to Q and R to S respectively, then

A. t₁ = t₂
B. t₁ < t₂
C. t₁ > t₂
D. Data insufficient
Answer : C

Question. The given figure shows primary and secondary rainbows.

Which of the following options correctly lists the colours of marked rays?
        1          2            3           4
A. Violet    Red       Red        Violet
B. Violet    Red       Violet     Red
C. Red      Violet     Violet     Red
D. Red      Violet     Red       Violet
Answer : A

Question. Seven identical resistors of resistance R each are connected as shown in the given figure.

If R₁, R₂ and R₃ are equivalent resistances between terminals A and B, between terminals C and D, and between terminals A and C respectively, then
A. R₁ = R₂ > R₃
B. R₁ = R₂ < R₃
C. R₁ < R₂ > R₃
D. R₁ > R₂ < R₃
Answer : C

Question. Four identical resistors are connected to a constant voltage supply as shown in the given figure.

If the maximum power consumed by each resistor is P when connected individually to the same voltage supply then the maximum power consumed by the combination will be
A. Zero
B. P
C. (4/3) P
D. (3/4) P
Answer : B

Question. An electric current passes through a straight wire.

Magnetic compass are placed at the points X and Y.
A. Their needles will not deflect.
B. Only one of the needles will deflect.
C. The needles will deflect in the same direction.
D. The needles will deflect in the opposite directions.
Answer : D

Question. Read the given statements and mark the correct option.
Statement 1 : Work done by the centripetal force in moving a body along a circle is always zero. 
Statement 2 : While moving in a circle, displacement of the body is along the centripetal force at each instant.
A. Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1.
B. Both statements 1 and 2 are true but statement 2 is not the correct explanation of statement 1.
C. Statement 1 is true but statement 2 is false.
D. Both statements 1 and 2 are false.
Answer : C

Question. Which of the following statements is/are incorrect?
(i) Energy received from the Sun in the form of radiation is called solar energy.
(ii) Sun is radiating energy at the rate of 4.5 × 10²³ kJ s^–1 approximately.
(iii) Solar energy is available in abundance without any cost.
(iv) Solar energy is the cause of wind, storm, rain and snowfall.
(v) Solar energy is pollution free.
A. (ii) only
B. (ii) and (iv) only
C. (i), (ii), (iii) and (v) only
D. None of these.
Answer : D

Question. An ionized gas contains both positive and negative ions. It is projected towards east to a region having uniform magnetic field directed into the plane of paper, then
A. Positive ions deflect towards north and negative ions deflect towards south
B. Positive ions deflect towards south and negative ions deflect towards north
C. All ions deflect towards south
D. All ions deflect towards north
Answer : A

Question. Four students P, Q, R and S noted the initial colour of the solutions kept in beakers I, II, III and IV. After inserting zinc rod in each solution and leaving them undisturbed for two hours, the colour of each solution was again noted in the given table.

Which student observed the colour change in all the four beakers correctly?
A. P
B. Q
C. R
D. S
Answer : D

Question. Which of the following organic compounds does not have the same chemical properties as methanol?
A. C₂H₆O
B. C₅H₁₀O
C. C₄H₁₀O
D. C₇H₁₆O
Answer : B

Question. If 20 g of each of the following substances is taken then, which one of them will contain the greatest number of atoms? (Atomic mass of C = 12 u, Na = 23 u, H = 1 u, F = 19 u)
A. Methane
B. Sodium
C. Hydrogen fluoride
D. Carbon
Answer : A

Question. The given apparatus shows the reaction of steam with eated solid ‘X’.

The equation for the reaction is Steam + Solid ‘X’ → Solid ‘Y’ + Gas ‘Z’ X, Y and Z are respectively
A. Copper, Copper oxide, Oxygen
B. Lead, Lead oxide, Hydrogen
C. Silver, Silver oxide, Oxygen
D. Iron, Iron oxide, Hydrogen.
Answer : D

Question. Melting and boiling points of five different substances are given in the table

Fill in the blanks by choosing an appropriate option. 
Substance (i) will have the least ordered arrangement of particles at room temperature.
Substances (ii) , (iii) and (iv) have a fixed volume but no fixed shape at room temperature. 
Substance (v) is solid at 100°C and is liquid at 200°C.
     (i)   (ii)   (iii)   (iv)   (v)
A. Q     S      P      T     R
B. P     Q      R      T     S
C. P     Q      R      S     T
D. R     P      Q      T     S
Answer : C

Question. Element M forms an ion, M²⁺ and element X forms an ion, X^2–. The electronic arrangements of these ions are shown as

Which of the following statements about the elements M and X is/are incorrect?
I. M is in group 2 and period 4 of the periodic table.
II. M is a non-metal and X is a metal.
III. X is in group 15 and period 2 of the periodic table.
IV. M and X form MX type compound.
V. On moving from M towards X in the periodic table, electronegativity decreases.
A. II, III and V
B. I and IV
C. Only II
D. II and III
Answer : A

Question. 0.1 mol of a basic substance (X) requires 25 cm³ of 8.0 mol/dm³ hydrochloric acid for complete neutralisation. X could be
1. Al(OH)₃  2. CuO
3. K₂O        4. NaOH
A. 1 and 2
B. 2 and 3
C. 1 and 4
D. 2 and 4
Answer : B

Question. For the given redox reaction :

Identify p, q, r and s.
A. p^-5, q^-10, r-oxidation, s-reduction
B. p^-8, q^-4, r-reduction, s-oxidation
C. p^-6, q^-3, r-oxidation, s-reduction
D. p^-10, q^-5, r-reduction, s-oxidation
Answer : D

Question. Observe the given figure carefully.

direction shown?
    Metal X           Metal Y
A. Copper           Zinc
B. Iron                Aluminium
C. Iron                Magnesium
D. Zinc               Silver
Answer : D

Question. A mixture consists of four substances. The properties of each of these substances are shown in the table

Magnesium nitrate decomposes on heating to form solid magnesium oxide, oxygen gas and nitrogen dioxide gas.
To obtain a pure dry sample of magnesium oxide from the mixture
A. First dissolve the mixture in water, then add dilute nitric acid to the filtrate and finally, heat it to dryness.
B. First dissolve the mixture in ethanol, then heat the filtrate to dryness.
C. First dissolve the mixture in ethanol, then dissolve the residue in dilute nitric acid and finally, heat the filtrate to dryness.
D. None of these.
Answer : C

Question. Mark the correct statement.
A. Latent heat of vaporisation is used to overcome the forces of attraction between molecules in solid state.
B. During the phase change, from solid to liquid and from liquid to gas, the temperature increases.
C. Incandescent light bulb is an example of plasma.
D. If a few spoons of salt are dissolved in pure water then its boiling point becomes more than 100°C.
Answer : D

Question. The schematic atomic structures of four elements are shown as

These elements can combine with each other to form different compounds. The possible compounds are
A. XW₃, W₂Z₃, ZY₂, YX₄
B. W₂Y₃, XZ₂, YZ₂, XY₄
C. WX₃, W₂Z₃, YZ₂, YX₄
D. WX₃, Z₂W₃, XY₄, YZ₂
Answer : C

Question. Match column I with column II and select the correct option from the given codes.
    Column I                      Column II
a. Plasma membrane      (i) Centrally located in animal cells
b. Cell wall                      (ii) Permeable
c. Lysosomes                 (iii) Selectively permeable
d. Nucleus                      (iv) Uncommon in plant cells
     a     b     c    d
A. (ii)   (i)  (iii) (iv)
B. (ii)  (iii) (iv)  (i)
C. (iii) (ii)  (iv)  (i)
D. (i)  (iv) (iii)  (ii)
Answer : C

Question. Read the following statements regarding epithelial tissues and select which of them are true and which of them are false.
(i) Epithelial tissue is protective tissue in animal body.
(ii) The lining of blood vessels, alveoli and kidney tubules are all made up of epithelial tissue.
(iii) Epithelial cells have a lot of intercellular spaces.
(iv) Epithelial tissues usually have no blood vessels.
(v) Epithelial tissues usually rest on a thin cellular basement membrane.
    (i)     (ii)    (iii)    (iv)    (v)
A.  F     F       T       T      F
B. T      F       F       F      F
C. T      T       F       T      T
D. T      T       F       T      F
Answer : D

Question. Which of the following statements about Spongilla, leech, dolphin and penguin is correct?
A. Penguin is homoiothermic while the remaining three are poikilothermic.
B. Leech is a freshwater form while all others are marine.
C. Spongilla has special collared cells called choanocytes, not found in the remaining three.
D. All are bilaterally symmetrical.
Answer : C

Question. In a plant, smooth seeds (S) are dominant over wrinkled seeds(s) and green seeds (G) are dominant over orange seeds (g). A plant homozygous for smooth and green seeds is crossed with a plant having wrinkled and orange seeds. The F₁ offspring are self-crossed to produce F₂ generation. If a total of 144 offspring are produced, how many plants are expected to be having wrinkled and green seeds in F₂ generation, according to a typical Mendelian cross?
A. 9
B. 18
C. 27
D. 81
Answer : C

Question. Read the given statements and select the correct option.
Statement 1 : A person who has already suffered from diseases like measles, small pox or chicken pox, becomes immune to subsequent attacks of these diseases.
Statement 2 : When a particular microbe invades the same person for the second time, the immune system responds rapidly with greater vigour and eliminates the infection more quickly than the first time.
A. Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1.
B. Both statements 1 and 2 are true but statement 2 is not the correct explanation of statement 1.
C. Statement 1 is true but statement 2 is false.
D. Statement 2 is true but statement 1 is false.
Answer : A

Question. New plants may be grown from groups of cells that are taken from same/other plants. The given diagram shows a part of plant X. 
Cell samples obtained from which of the labelled structures will grow into new plants that are genetically identical to plant X?

A. P
B. Q
C. R
D. S
Answer : D

Question. The pea plant develops tendrils which help it to climb up a support. Which of the following statements is not true regarding the movement of tendrils in pea plant?
A. As the tendrils come in contact with a support, the part of tendril away from the support grows faster than the part in contact with the support.
B. More auxin is diffused from its site of synthesis towards the side of tendril in contact with the support than the side away from the support.
C. The side of the tendril having more auxin grows faster than the side having less auxin.
D. The tendrils exhibit directional movement due to growth in response to touch.
Answer : B

Question. Read the given paragraph carefully.
Red-coloured beetles are living on green leaves of bushes. These beetles increase in numbers by sexual reproduction. Crows, being their predators, consume beetles and regulate their population. During reproduction, few beetles develop green colour instead of red colour. This variation in body colour gives green coloured beetles an advantage and over the years, the number of green beetles in the population will increase generation after generation.
Which of the following statements are correct regarding the given paragraph.
(i) The given paragraph depicts an example of ontogeny recapitulates phylogeny.
(ii) Artificial selection is exerted by crows.
(iii) Natural selection is exerted by crows.
(iv) More red-coloured beetles will be eaten up.
(v) The given paragraph depicts an example of convergent evolution.
A. (i), (iv) and (v) only
B. (iii) and (iv) only
C. (i), (ii) and (iii) only
D. (ii) and (v) only
Answer : B

Question. In a grassland, a large population of grass supports a fewer number of grasshoppers that support a smaller number of frogs. The latter support still smaller number of snakes and the snakes support very few falcons. Which of the following correctly represents the pyramid of numbers in this grassland?

Answer : C

Question. Which of the following contraceptive methods does not correctly match with its mode of action?

Answer : C

Question. Refer to the given diagram of human digestive system.

Digestive juices P, Q and R were collected from structures labelled as 1, 2 and 3 respectively. The digestive juices were then mixed with a buffer solution of pH = 2. Small drops of these juices were then put on a strip of film coated with protein. Which of the following digestive juices will be able to digest the protein coat?
A. Digestive juice P only
B. Digestive juice Q only
C. Digestive juice R only
D. Both digestive juices Q and R
Answer : B

Achievers Section

Question. Two v – u graphs are plotted using the new Cartesian sign conventions. Here v and u denote the distance of image and distance of object from pole (or optical centre) respectively.

The graphs correspond to
            (i)                              (ii)
A. Convex mirror          Convex lens
B. Convex mirror          Concave lens
C. Concave mirror        Convex lens
D. Concave mirror        Concave lens
Answer : C

Direction : Refer to the given paragraph and answer the questions a and b.
A scale for measuring hydrogen ion concentration in a solution is called pH scale. The p in pH stands for ‘potenz’ in German, meaning power. On the pH scale we can measure pH generally from 0 to 14. pH should be thought of simply as a number which indicates the acidic or basic nature of a solution.

Question a. pH of different solutions are given in the table.

Arrange these solutions in the increasing order of OH– ion concentration.
A. S < R < Q < P
B. P < R < S < Q
C. R < S < Q < P
D. Q < S < R < P
Answer : B

Question b. Which of the following graphs shows the change in pH when zinc carbonate is added to hydrochloric acid until it is in excess?

Answer : C

Question. The thyrotropin releasing hormone (TRH) from the (1) stimulates the (2) to secrete the thyroid stimulating hormone (TSH), which in turn stimulates the thyroid gland to secrete thyroxine. A (3) amount of thyroxine in the blood exerts (4) effect on (1) so that (5) TRH and TSH are produced. This eventually results in a (6) in thyroxine. It is called (7) feed back control. 
Select the option that correctly fills up the blanks in the above passage.
A. ( 1 ) - P o s t e r i o r l o b e o f p i t u i t a r y g l a n d , (2)-Hypothalamus, (3)-Low, (4)-Inhibitory, (5)-Lesser, (6)-Decrease, (7)-Negative
B. (1)-Hypothalamus, (2)-Posterior lobe of pituitary gland, (3)-Lesser, (4)-Stimulatory, (5)-More, (6)-Increase, (7)-Positive
C. (1)-Hypothalamus, (2)-Anterior lobe of pituitary gland, (3)-High, (4)-Inhibitory, (5)-Lesser, (6)-Decrease, (7)-Negative
D. ( 1 ) - A n t e r i o r l o b e o f p i t u i t a r y g l a n d , (2) Hypothalamus, (3)-High, (4)-Stimulatory, (5)-More, (6)-Increase, (7)-Positive
Answer : C

Question. Embryology refers to the study of development of an embryo of an organism from fertilised egg to young one. Given figures represent the early embryos of certain organisms (fish, reptile, bird and human). 

Select the correct inference drawn from these figures.
A. An organism repeats its ancestral history during its embryonic development.
B. Early embryos of all vertebrates exemplify homologous structures and divergent evolution.
C. Dissimilarity in the embryos of different vertebrates shows that all the vertebrates have evolved from different ancestors.
D. The complex body structures of embryos gave rise to simple body structures of adults.
Answer : B