CBSE Class 10 Science NSO Olympiad MCQs with Answers Set A

Logical reasoning

Question. If yesterday was Saturday’s tomorrow and tomorrow is Wednesday’s yesterday, then what day would it be today?
A. Sunday
B. Monday
C. Tuesday
D. Friday
Answer : B

Question. In the following letter series, some of the letters are missing which are given in that order as one of the options below it. Select the correct option. ba__ cb__ b__ bab__
A. acbb
B. bacc
C. bcab
D. cabb
Answer : B

Question. Study the following information and answer the question given below.
I. A, B, C, D, E, F, G and H are standing in a row facing North.
II. B is not a neighbour of G.
III. F is at the immediate right of G and neighbour of E.
IV. G is not at the extreme end.
V. A is sixth to the left of E.
VI. H is sixth to the right of C.
After making the linear arrangement, we join them to form a circular arrangement by joining A and H. Which of the following is the odd one out?
A. B-D
B. E-F
C. A-C
D. H-G
Answer : D

Question. The positions of four policemen A, B, C and D is given in a circular park. The park is divided into sixteen plots. P, Q, R and K are the offenders whom they have to catch after given moves. The given figure shows their positions. (Note that the by-lanes are North-South and East-West.)

If A, B, C and D were to move clockwise four plots and P, Q, R and K were to move anti-clockwise six plots, then out of the given options, who two would be North and South respectively?
A. P and A
B. R and D
C. Q and B
D. P and C
Answer : B

Question. In the following number series, how many 4s are there, which are immediately preceded by a pair of numbers whose product is more than the product of the pair of numbers immediately following 4?
5 3 4 6 4 8 9 4 7 6 4 5 7 4 8 4 4 8 0 2 3 4 3 1 4 7 2
A. 4
B. 5
C. 6
D. 2
Answer : B

Question. There are seven figures, the first and last of which are unmarked, and the remaining are marked as P, Q, R, S and T. These seven figures form a series.
However, one of the five marked figures does not fit into the series. Identify that figure in the given options.

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

Question. A large cube is dipped into a tub filled with colour. When the cube is taken out, it is observed that all its sides are painted. This large cube is now cut into 125 small but identical cubes. How many of the smaller cubes have exactly three faces painted?
A. 4
B. 8
C. 9
D. None of these
Answer : B

Question. Select the mirror image of given combination, if the mirror is placed vertically to the left.
NicaRaGuA

Answer : D

Question. Following two figures show the expenditure on various items by families A and B. Which of the conclusions given below is not correct?

A. A spends more on food than B.
B. B spends more on clothing than A.
C. B spends equal amounts on food and clothing.
D. A spends more on rent than on any other item.
Answer : D

Question. In a certain code language, the letters immediate next to vowels are replaced with D, all other consonants with preceding letters and the vowels are replaced with Z. How will the word STANDING be written in that code language?
A. RSZMCZMF
B. TSZMCZFM
C. RSZMCZDF
D. RSZDCZDF
Answer : D

Question. In the following question, a related pair of figures is followed by four other pairs of figures. Out of the four pairs, select the pair that has a relationship similar to that in the question pair. The best answer is to be selected from a group of fairly close choices.

Answer : C

Question. A set of figures carrying certain characters is given. Assuming that the characters in each set follow a similar pattern, find the missing character.

A. 13
B. 15
C. 17
D. 19
Answer : B

Question. Select the figure from the options which will replace the question mark (?) in the given series.

Answer : D

Question. P is the son of Q while Q and R are sisters to one another. T is the mother of R. If S is the son of T, which of the following statements is correct?
A. T is the brother of Q.
B. S is the cousin of P.
C. Q and S are sisters.
D. S is the maternal uncle of P.
Answer : D

Question. Figures P, Q and R shows a sequence of folding of a piece of paper. Figure R shows the manner in which the folded paper has been cut. Select a figure from the options which would most closely resemble the unfolded form of figure R.

Answer : C

Science

Question. A body is suspended from a spring balance kept in 
a satellite. The reading of the balance is W₁ when the satellite goes in an orbit of radius R and is W₂ when it goes in an orbit of radius 2R. Then
A. W₁ = W₂
B. W₁ < W₂
C. W₁ > W₂
D. W₁ ≠ W₂
Answer : A

Question. Read the given statements and mark the correct option.
Statement 1 : Magnetic field is not associated with a stationary charge.
Statement 2 : Magnetic field can be detected by means of its effect on a current carrying conductor.
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 : B

Question. Three identical resistors are connected across a voltage source V such that one of them is in parallel with other two, which are connected in series as shown.
The power dissipated through the first one, compared to the power dissipated by each of the other two is _______.

A. The same
B. Half as much
C. Twice as much
D. Four times as much
Answer : D

Question. A coordinate axis as shown in figure is kept in front of a converging lens at a distance 2f from it, where f is the focal length of the lens.
Which of the following shows the approximate shape of the image? Assume that X-axis is the principal axis of the lens

Answer : A

Question. A box of mass 2 kg has an initial speed of 10 m s^–1 at the foot of the ramp Given that the friction along the ramp is 2 N, find the height h that the box reaches when its speed is 5 m s^–1.
(Take g = 10 N kg^–1)

A. 2.5 m
B. 3.4 m
C. 4.0 m
D. 6.0 m
Answer : B

Question. A boy stands between two vertical walls. After making a loud clap, he hears two echoes at an interval of 1 s. If the distance between the two walls is 1000 m, what is his distance from the nearest wall?
(Take speed of sound = 300 m s^–1).
A. 425 m
B. 215 m
C. 265 m
D. 365 m
Answer : A

Question. Energy released in the fission of 1 kg of U-235 is equivalent to energy obtained from burning of coal weighing approximately ______.
A. 25 ton
B. 250 ton
C. 2500 ton
D. 25000 ton
Answer : C

Question. A glass sphere of radius 1 m and refractive index 3/2 is silvered at its back. A point object is kept at a distance of 1 m from the front face, as shown in figure. Find the position of the final image.

A. (−5/7) m
B. (7/5) m
C. (−13/7) m 
D. (7/13) m
Answer : C

Question. A charged particle enters a uniform magnetic field perpendicular to its initial direction, travelling in air.
The particle is seen to follow the path as shown in the figure.

(i) The magnetic field strength may have been increased while the particle was travelling in air.
(ii) The particle lost energy by ionising the air.
(iii) The particle lost charge by ionising the air.
Which of the above statements is/are correct?
A. (ii) only
B. (i) and (ii)
C. (ii) and (iii)
D. (i), (ii) and (iii)
Answer : B

Question. The height of mercury in a barometer at sea level is higher than that at the top of a hill. Which of the following inferences about this observation is correct?
A. The air molecules at sea level have higher mass than that of at the top of a hill.
B. The air molecules at sea level experience less gravitational force than that of at the top of a hill.
C. The air molecules per unit volume at sea level are greater than that of at the top of a hill.
D. The speed of air molecules at sea level is lower than that of at the top of a hill.
Answer : C

Question. Nandita mixed two solutions X and Y. She recorded the following observations and conclusions in her notebook.
I. A yellow precipitate is formed.
II. It is a double displacement reaction.
The solutions X and Y respectively are
A. Pb(NO₃)₂, KI
B. AgNO₃, NaCl
C. Na₂SO₄, BaCl₂
D. FeCl₃, NH₄OH
Answer : A

Question. Which of the following is not an isotope of the other three?

Answer : B

Question. Compound X decolourises acidified potassium dichromate to produce an acid with a pH value of 4.5. Which of the following could be the structure of X?
A. CH₃CH₂COOH
B. CH₃CH₂CH₂OH
C. CH₂ = CH — CH₃
D. CH₃CH₂CH₃
Answer : B

Question. The positions of four elements K, L, M and N in the periodic table are shown below :

Which of the following statements are correct?
I. K, L, M and N are metalloids.
II. K is a metal while L, M and N are non-metals.
III. Among these four elements, K is the smallest in size.
IV. K is a metal while L and M are metalloids and N is a non‑metal.
A. II and III
B. I and III
C. III and IV
D. None of these
Answer : B

Question. Five students have different amounts of substances.
Nitika : 6.022 × 10²⁴ atoms of Ca
Sagar : 2 g of C
Pooja : 0.5 g atom of Ag
Ranjan : 0.3 mole of H₂SO₄
Yash : 6.022 × 10²⁵ atoms of CO₂
[At. wts. of Ag = 108 u, S = 32 u, Ca = 40 u, C = 12 u,
H = 1 u, O = 16 u]
Arrange the students in decreasing order of masses of the substances that they have.
A. Sagar > Ranjan > Pooja > Nitika > Yash
B. Yash > Nitika > Ranjan > Pooja > Sagar
C. Yash > Nitika > Pooja > Ranjan > Sagar
D. Pooja > Sagar > Yash > Ranjan > Nitika
Answer : C

Question. Four solutions labelled as P, Q, R and S have pH values 1, 9, 3 and 13 respectively.
Which of the following statements about the given solutions is incorrect?
A. Solution P has higher concentration of hydrogen ions than solution R.
B. Solution Q has lower concentration of hydroxyl ions than solution S.
C. Solutions P and Q will turn red litmus solution blue.
D. Solution P is highly acidic while solution Q is weakly basic.
Answer : C

Question. The atomic numbers of some elements are given below :

The number of valence electrons 8, 2, 1, 7 and 5 respectively are present in
A. Q, P, O, N, M
B. N, O, Q, M, P
C. P, Q, O, N, M
D. O, P, N, M, Q
Answer : C

Question. Three hydrocarbons X, Y and Z are shown below:
X : CH₃CH₂CH₂CH₂CH₃; Y :
Z : CH₃CH₂ — CH = CH — CH₃
Identify the incorrect statements about these three hydrocarbons.
I. X and Y both differ by a — CH₂ unit.
II. X and Z have the same boiling point.
III. All have different general formulae.
IV. Y and Z have different molecular masses.
A. I and II
B. II and III
C. I and IV
D. All the statements are incorrect.
Answer : A

Question. Study the given graphs carefully.

Which of the following statements is correct?
A. The melting point of the substance P is 200°C.
B. The boiling point of the substance Q is 50°C.
C. At point ‘b’, the substance P exists in both solid and liquid states.
D. At point ‘x’, the substance Q exists in both liquid and gaseous states while at point ‘d’, the substance P exists in both gaseous and liquid states.
Answer : C

Question. Aditya accidentally mixed copper sulphate crystals with sand. How can he recover the copper sulphate crystals?
1. Add water to the mixture and filter.
2. Evaporate the filtrate to dryness.
3. Heat the filtrate until it is saturated, and let it cool.
4. Wash the residue, and dry it between sheets of filter paper.
A. 1 and 2
B. 1 and 3
C. 1, 2 and 4
D. 1 and 4
Answer : B

Question. Identify the given organisms, match them with their peculiar features as shown in the table and select the option with all the correct matches.

A. P, R, U, V P, S, V P, S, W, U Q, S, V, W
B. P, R, V, T P, S, V P, S, U, W Q, S, U, W
C. P, R, U, V P, S, V Q, S, W, U Q, S, T, W
D. P, R, V, T P, S, V P, S, W, U Q, S, T, W
Answer : D

Question. Albumin is the most abundant protein in blood plasma, accounting for approximately 60% of all plasma protein. A person was found to have reduced level of plasma albumin due to kidney damage. Which of the labelled part(s) would you expect to be the primary site of damage for this patient?

A. U, T
B. P only
C. R only
D. P, Q, S
Answer : B

Question. Four seedlings of equal size and length are taken and given different treatments:
Plant P : Tip not removed, nothing applied.
Plant Q : Tip removed, nothing applied.
Plant R : Tip removed, gelatin block was placed on cut edge.
Plant S : Tip removed, gelatin block with auxin was placed on cut edge.
What would be the correct order of growth rates of the plants?
A. S > P > R > Q
B. S > R > P > Q
C. P > R > Q > S
D. P > S > Q > R
Answer : A

Question. Given are different parts of respiratory tract.
P. Nasal cavity Q. Alveolar duct
R. Larynx
S. Respiratory bronchioles
T. Epiglottis U. Terminal bronchioles
V. Lobular bronchioles W. Trachea
X. Bronchus
Which path a molecule of carbon dioxide in the alveolus of the inferior lobe of lung takes on its journey to the outside?
A. Q → U → S → V → X → W → R → T → P
B. Q → S → U → V → X → W → T → R → P
C. Q → S → U → V → X → W → R → T → P
D. Q → S → U → X → V → W → R → T → P
Answer : C

Question. A large forest area got burnt in a massive fire. The species that would invade such bared area to rapidly colonize it have __________ , __________ and __________ characteristics.
Fill up the blanks from the given choices and select the correct option.
(i) Long lifespan (ii) Rapid reproduction
(iii) Fast growth
(iv) Strong dispersal ability
(v) Strong defense against natural enemies or predators.
(vi) Large sized individuals
A. (i), (ii), (iii)
B. (ii), (iii), (iv)
C. (i), (iv), (vi)
D. (iii), (iv), (vi)
Answer : B

Question. (i) SER (ii) Golgi apparatus
(iii) Lysosome (iv) RER
(v) Ribosome (vi) ER
Using the words in the box complete the synthesis process of digestive enzymes before their exocytosis then select the option that will complete the following passage correctly.
1. The (a) provides extensive surface on which (b) carry protein synthesis or synthesis of digestive enzymes.
2. Synthesized enzymes enter (c) and then (d) for modification.
3. The modified enzymes are stored in (e) which pass outwardly and fuse with plasma membrane during exocytosis.
     (a) (b) (c) (d) (e)
A. (iv) (v) (vi) (ii) (iii)
B. (iv) (v) (vi) (iii) (ii)
C. (i)  (v) (vi) (ii) (iii)
D. (i)  (v) (vi) (iii) (ii)
Answer : A

Question. R is an organic compound containing only carbon, chlorine and fluorine. It is produced as a volatile derivative of methane, ethane and propane. It has been widely used as refrigerant, propellent and solvent. Montreal protocol phased out manufacture of such compounds because R contributes to S in the atmosphere.
Which of the following would not be a consequence of S?

A. Increased incidence of severe sunburns
B. Increased incidence of cataracts
C. Increased incidence of premature skin aging
D. Increased rates of lung cancer
Answer : D

Question. Rohan made the following statements regarding the section of a tissue as shown in the given figure.

(i) It provides mechanical support to the plants.
(ii) Its cell wall shows localized thickenings.
(iii) Cells are dead.
(iv) Cells are filled with protoplasm and have narrow lumen.
(v) Cells have hard secondary walls.
(vi) It is distributed in almost all parts of the plant body.
Which among them are incorrect?
A. (i), (iii), (iv), (v)
B. (ii), (iv), (v), (vi)
C. (ii), (iv), (vi)
D. (ii), (iv), (v)
Answer : C

Question. The given graph shows the concentration of dissolved oxygen along a river. At which point is sewage emptied into the river?
A. P
B. Q
C. R
D. S
Answer : C

Question. Match Column-I with Column-II and select the correct option from the codes given below.
      Column-I                                      Column-II
(a) Increased egg production            (i) Viral disease
(b) White leghorn                              (ii) Carp
(c) Ranikhet                                      (iii) Fish by-product
(d) Isinglass                                      (iv) Layers
(e) Silver carp                                   (v) Exotic fish
(f) Bombay duck                               (vi) Silver revolution
(g) Rohu and Catla                          (vii) Marine fish
     (a)   (b)   (c)    (d)   (e)   (f)    (g)
A. (iv)   (vi)   (i)    (iii)   (v)  (vii)   (ii)
B. (vi)   (iv)   (i)    (iii)  (vii)  (v)    (ii)
C. (vi)   (iv)   (i)   (vii)   (v)   (iii)   (ii)
D. (vi)   (iv)   (i)   (iii)   (v)   (vii)   (ii)
Answer : D

Achievers Section

Direction: Refer to the given passage and answer the following questions.
Metals are extracted from their ores by different methods depending on their position in the activity series.

Question. Match the Column-I with Column-II and select the correct option from the codes given below.
      Column-I                            Column-II
(a) Highly reactive metals           (i)    S
(b) Calcination                           (ii)    T
(c) Electrolytic reduction            (iii)    P
(d) Less reactive metals             (iv)    R
(e) Roasting                               (v)    Q
A. (a)-(v), (b)-(ii), (c)-(iv), (d)-(iii), (e)-(i)
B. (a)-(iv), (b)-(ii), (c)-(v), (d)-(iii), (e)-(i)
C. (a)-(iii), (b)-(ii), (c)-(iv), (d)-(v), (e)-(i)
D. (a)-(i),  (b)-(ii), (c)-(v), (d)-(iii), (e)-(iv)
Answer : C

Question. Metals which are extracted by heating, electrolysis
and by reduction with carbon respectively are
A. Copper, magnesium, zinc
B. Mercury, aluminium, lead
C. Mercury, sodium, calcium
D. Both A and B
Answer : D

Question. The dwarf variety of garden pea plants are now known to have a mutation in a gene needed for synthesis of gibberellin. F1 plant obtained by Mendel from the tall (TT) × dwarf (tt) cross were tall.
Which of the following inferences can be drawn from the given information?
(i) Gibberellin causes elongation of stems.
(ii) Heterozygous (Tt) plants produce the same amount of gibberellin as homozygous dominant (TT)  plants.
(iii) Gibberellin induces production of auxin.
(iv) Mutation may have occurred in a gene producing an enzyme.
A. (i) and (ii)
B. (ii), (iii) and (iv)
C. (i), (ii), (iii) and (iv)
D. (i), (ii) and (iv)
Answer : D

Question. The given figure shows monthly changes in the human ovary during the reproductive cycle.

Which of the following statements is most accurate regarding the labelled structure(s)?
A. Before puberty, only structure ‘T’ undergoes meiosis.
B. The hormone produced by structure ‘R’ stimulates the pituitary gland to secrete luteinizing hormone.
C. The hormone produced by structure ‘S’ is responsible for the development of female secondary sex characters.
D. The hormones produced by ‘P’ and ‘Q’ stimulate the proliferation of the endometrial lining of the uterine wall.
Answer : D

Question. A particle starts from rest at time t = 0 and moves in a straight line with acceleration as plotted in given graph. The speed of the particle will be maximum at time ____.

A. 1 s
B. 2 s
C. 3 s
D. 4 s
Answer : B