CBSE Class 10 Science NSO Olympiad MCQs with Answers Set J

LOGICAL REASONING

Question. If in a certain code language, ‘WON’ is written as ‘VXNPMO’, then how will ‘SOUTH’ be written in the same language?
A. IGUSVTPNTR
B. RTNPTVSUGI
C. RTNPTVSVGI
D. RTNPTVRUGI
Answer : B

Question. Select a figure from the options which will complete the series as established by the Problem Figures

Answer : A

Question. Z is the father of Q. A is the daughter of Y and Y is the son of Z. If P is the son of Y and B is the brother of P, then which of the following options is definitely correct?
A. B and Y are brothers
B. A is the sister of B
C. Z is the uncle of B
D. Q and Y are brothers
Answer : B

Question. In which of the following options, the given figure is exactly embedded as one of its parts?

Answer : C

Question. There is a set of four figures P, Q, R and S showing a sequence of folding of a piece of paper. Figure (S) 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 fig. (S).

Answer : A

Question. In the given question, two rows of numbers are given.
The resultant number in each row is to be worked out separately based on the following rules and the question below the rows of numbers is to be answered. The operations on numbers progress from left to right.
Rules:
(i) If an odd number is followed by another composite odd number, they are to be added.
(ii) If an even number is followed by an odd number, they are to be added.
(iii) If an even number is followed by a number which is the perfect square, the even number is to be subtracted from the perfect square.
(iv) If an odd number is followed by a prime odd number, the first number is to be divided by the second number.
(v) If an odd number is followed by an even number, the second one is to be subtracted from the first number.
                                     36 15 3
                                     12  3  n
If ‘n’ and ‘m’ are the resultants of the first row and second row respectively, then 17 × m is _______.
A. 5
B. 17
C. 15
D. 36
Answer : C

Question. Puneet travels 5 m in North direction, then he turns right and travels 10 m. Again he turns towards right and travels 20 m . Then he turns towards left and travels 10 m. In which direction and how far is Puneet from his original position?
A. 35 m, East
B. 10 m, West
C. 25 m, East
D. None of these
Answer : B

Question. Which of the following options satisfies the same conditions of placement of dots as in the given figure?

Answer : B

Question. Three positions of a dice are shown below. Which number is on the face opposite to the face having number 2?

A. 6
B. 3
C. 4
D. 5
Answer : D

Question. Find the missing number.

A. 38
B. 66
C. 68
D. 70
Answer : D

SCIENCE

Question. A hollow metal of mass 180.6 g contains cavity of volume 2.5 cm³. This metal when placed in water displaces 24 cc of water. Find the specific gravity of metal.
A. 7.6
B. 8.4
C. 10.5
D. 7.2
Answer : B

Question. In the given circuit, R₁ = R₂ and V is applied voltage.
The values of V and R₁ are respectively

A. 180 V and 60 Ω
B. 120 V and 60 Ω
C. 180 V and 10 Ω
D. 120 V and 10 Ω
Answer : A

Question. An electric current is passed through a straight wire as shown. If two magnetic compasses are placed at the points X and Y, then

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. Which of the following statements is/are incorrect?
I. A person suffering from hypermetropia cannot see the distant objects clearly.
II. When eye muscles are relaxed and lens becomes thinner, then the focal length of the eye lens increases.
III. Twinkling of stars is due to atmospheric refraction of light by different layers of varying refractive indices.
IV. The change in focal length of the eye lens is caused by the action of iris.
A. I only
B. IV only
C. II and III only
D. I and IV only
Answer : D

Question. The diagrams show the relative motion between a magnet and a solenoid. A galvanometer is connected to the solenoid to detect the induced current. Which diagram shows no deflection in the galvanometer?

Answer : D

Question. A beam of light reflects and refracts at point P, as shown in the diagram. Find the angle of refraction at point P. n₁ and n₂ are refractive indices of media.

A. 60°
B. 45°
C. 30°
D. None of these
Answer : C

Question. The square in the diagram outlines the points where a beam of electrons, moving into the plane of paper, enters a magnetic field. What will happen to the particles?

A. Deflect to the left
B. Deflect to the right
C. Deflect upwards
D. Deflect downwards
Answer : C

Question. The velocity-time (v - t) graph for a particle moving on a straight line is shown here. Which of the following statements is correct?

A. The particle has a variable acceleration.
B. The particle has never turned around.
C. The particle has zero displacement.
D. The average speed in the interval 0 to 5 s is the same as the average speed in the interval 5 to 10 s.
Answer : D

Question. Initially, four identical uniform blocks, each of mass m and thickness h, are placed on a table as shown in figure (i). How much work is done on the blocks in stacking them on top of one another as shown in figure (ii)?

A. 2 mgh
B. 3 mgh
C. 4 mgh
D. 6 mgh
Answer : D

Question. Read the given statements and select the correct option.
Statement 1 : Loudness is the characteristic of a musical sound by which a loud sound can be distinguished from a faint sound.
Statement 2 : Echo is always produced when sound is incident on hard and polished surface.
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 1 is false but statement 2 is true.
Answer : C

Question. A battery of 6 V is connected in series to a 10 W resistor and a parallel combination of resistors of resistance 6 W and R. The battery delivers a current of 0.5 A to circuit as shown. What are the values of the unknown current I and the resistance R?

     I(A)    R(W)
A. 0.17      9
B. 0.25      4
C. 0.25      6
D. 0.33      3
Answer : D

Question. A spherical planet has a mass Mp and diameter Dp. A particle of mass m falling freely near the surface of this planet will experience an acceleration due to gravity equal to
A. 4GM_p/Dp²
B. 4GM_pm/Dp²
C. GM_p/Dp²
D. 4GM_pm/Dp²
Answer : A

Question. Four students Shristi, Preeti, Abhishek and Sidh performed the experiment to study the reactions of dilute hydrochloric acid and solution of sodium hydroxide with zinc metal and solid sodium carbonate separately.
They tabulated their observations in the given table

The correct observations in all the four sets are shown by
A. Shristi only
B. Sidh only
C. Abhishek only
D. Preeti only.
Answer : B

Question. In the given Venn diagram, points 1, 2 and 3 represent different colloidal systems.
Which of the following best represents points 1, 2 and 3?

         1               2                             3
A. Cheese    Milk                        Fog
B. Paint       Sponge                   Shaving cream
C. Bread     Milk of magnesia     Froth
D. Curd       Gold sol                  Cheese
Answer : B

Question. P, Q, R, S, T and U are six consecutive elements of the periodic table. The given table shows the formulae of the oxides of these elements.

Read the given statements carefully.
I. Element Q belongs to group 15 and period 3.
II. The elements P and S form a covalent compound of type PS₄.
III. Element R belongs to group 14 and period 2.
IV. The elements U and S form an ionic compound of type U₂S.
The correct statement(s) is/are
A. I only
B. I, II and IV only
C. I and II only
D. III and IV only.
Answer : C

Question. Three different states of matter are shown in figures 1, 2 and 3.

Melting and boiling points of three substances P, Q and R are given in the table

Read the given passage carefully and fill in the blanks by selecting an appropriate option. 
The substance(s) which exist(s) in state (3) at room temperature is/are (i) . The substance(s) which exist(s) in state (1) at 100°C is/are (ii) . The substance(s) which exist(s) in state (2) at 15°C is/are (iii) .
     (i)       (ii)     (iii)
A. Q      P, R      P
B. P      Q          Q, R
C. P, R  P          Q
D. Q      P, R      R
Answer : A

Question. Study the given flow chart carefully.

Which of the following statements is/are correct?
I. P is propanol and it liberates hydrogen gas on reaction with sodium metal.
II. Q is a saturated hydrocarbon which decolourises Br₂-water.
III. P and S react together in presence of conc. H₂SO₄ to give a sweet smelling compound.
IV. U when passed through lime water, turns it milky.
A. I, III and IV only
B. I and IV only
C. II only
D. I, II, III and IV
Answer : A

Question. The number of atoms of Na, H, S and O in 0.5 mole of sodium bisulphite are respectively
(Given : Atomic mass of Na = 23 u, H = 1 u, S = 32 u and O = 16 u)
A. 3.01 × 10²³, 3.01 × 10²³, 3.01 × 10²³ and 9.03 × 10²³
B. 9.03 × 10²³, 3.01 × 10²³, 6.023 × 10²³ and 1.5 × 10²³
C. 3.01 × 10²¹, 9.03 × 10²³, 4.5 × 1022 and 3.0 × 10²¹
D. 3.01 × 10²³, 3.01 × 10²³, 3.01 × 10²³ and 3.01 × 10²³
Answer : A

Question. Baking powder is a mixture of X and a mild edible acid such as Y. When it is heated, Z is produced which makes bread and cake soft and spongy. X, Y and Z are respectively
A. Sodium hydrogen carbonate, tartaric acid, CO₂
B. Sodium carbonate, acetic acid, CO₂
C. Sodium hydroxide, acetic acid, H₂
D. Sodium chloride, oxalic acid, H₂.
Answer : A

Question. Abhiruchi, a class 10 student took clean small pieces of magnesium, aluminium, zinc, iron and copper in separate test tubes. She added about 10 mL of dilute hydrochloric acid to each of them.

Identify the incorrect statement(s).
A. The rate of evolution of hydrogen gas bubbles is same in all the test tubes as all are metals.
B. The reactivity decreases in the order : Mg > Zn > Al > Fe > Cu
C. In case of copper, no bubbles are seen and the temperature also remains unchanged.
D. Both A and B.
Answer : D

Question. Read the given statements and select the correct option.
Statement 1 : The components of azeotropes cannot be separated by fractional distillation.
Statement 2 : The components of azeotropes form a constant boiling mixture.
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 : A

Question. Match column I with column II and select the correct option from the given codes.
                Column I                       Column II
    (Methods of extraction)             (Metals)
P. Reduction with aluminium           (i) Mercury
Q. By electrolysis                          (ii) Calcium
R. Reduction with carbon               (iii) Manganese
S. By heating alone (iv) Zinc
A. P-(iii), Q-(ii), R-(iv), S-(i)
B. P-(iii), Q-(iv), R-(ii), S-(i)
C. P-(iv), Q-(iii), R-(i), S-(ii)
D. P-(ii), Q-(i), R-(iii), S-(iv)
Answer : A

Question. A few redox reactions are given as follows :
I. Cu + 2AgNO₃ → Cu(NO₃)₂ + 2Ag
II. 3MnO₂ + 4Al → 3Mn + 2Al₂O₃
III. 2HI + Cl₂ → 2HCl + I₂
IV. Fe₂O₃ + 3CO → 2Fe + 3CO₂
Select the correct option.
A. In reaction I, copper is an oxidising agent.
B. In reaction II, MnO2 is oxidised.
C. In reaction III, HI is the reducing agent.
D. In reaction IV, CO is reduced.
Answer : C

Question. The composition of five particles U, V, W, X and Y is given in the table

Identify atoms, ions and isotopes.
        Atoms        Ions        Isotopes
A. U, V, W, X          Y          X and Y
B. W, Y              U, V, X      V and W
C. U, V, W, X          Y          V and W
D. V, W              U, Y          X and Y
Answer : C

Question. Refer to the given graph Identify factors P and Q from the given graph and select the correct option regarding it.

A. P could be temperature whereas Q could be light intensity.
B. P could be relative humidity whereas Q could be air movement.
C. P could be light intensity whereas Q could be relative humidity.
D. P could be light intensity whereas Q could be temperature.
Answer : C

Question. Identify figures (i)-(iv) and select the correct option regarding them

A. Both (i) and (iv) exhibit cellular level of body organisation.
B. (ii) is acoelomate whereas (iii) is coelomate.
C. (i) and (ii) are diploblastic whereas (iii) and (iv) are triploblastic.
D. Symmetry is radial in (i) and adult form of (iv) whereas bilateral in (ii) and (iii).
Answer : D

Question. Which of the following statements is incorrect?
A. Placenta allows exchange of materials between mother and fetus.
B. The fetal part of the placenta consists of the cells of the chorion which produce projections called chorionic villi.
C. Antibody cannot cross the placenta from mother to fetus.
D. Placenta secretes pregnancy hormones required for supporting fetal growth and metabolic changes in mother during pregnancy.
Answer : C

Question. Which of the following statements is incorrect?
A. Mitochondria, unless specifically stained are not easily visible under the microscope.
B. Physiological activity of cells determines the number of mitochondria per cell.
C. Mitochondrion, a power house of cell has DNA, RNA, ribosomes and enzymes, so it can survive outside the cell.
D. Mitochondria divide by fission.
Answer : C

Question. Select the correct statement.
A. Amount of greenhouse gases i.e., CO, CO₂, CFCs and CH₄ is decreasing due to harmful activities in atmosphere.
B. Increase in average global temperature could lead to melting of polar ice caps.
C. Ozone layer present in mesosphere, protects earth from harmful effects of solar radiations.
D. Putrefying bacteria help to convert ammonia into nitrites and then into nitrates.
Answer : B

Question. Select the incorrect statement.
A. Economic development is linked to environmental conservation.
B. Sustainable development encourages development for current generation and conservation of resources for future generations.
C. Sustainable development does not consider the view points of stakeholders.
D. Sustainable development is a long, planned and persistent development.
Answer : C

Question. Study the given situation.
Plants that beetles feed upon suffered from a disease and died. Due to reduced food, beetles are poorly nourished and show reduced weight. But there is no genetic change. After few years plant disease is eliminated. Now abundance of leaf food causes weight gain in next beetle generations.
Which of the following statements best explains the given situation?
A. Natural selection is the phenomenon where nature selects organism having traits favourable to the environment.
B. Acquired trait does not bring any change in the DNA and therefore this trait is not inherited.
C. Speciation leads to the formation of species due to reproductive isolation.
D. Genetic drift leads to elimination of genes of certain traits from a small population when a section of the species population dies of natural calamity.
Answer : B

Question. Which of the following statements is/are incorrect regarding connective tissues?
(i) They are the most abundant and widely distributed in the body of complex animals.
(ii) They connect and support other tissues.
(iii) They include diverse tissues such as bones, cartilage, tendons, adipose and other loose connective tissues.
(iv) They form the internal and external lining of many organs.
A. (iv) only
B. (ii) only
C. (i) and (ii) only
D. (iii) and (iv) only
Answer : A

Question. Refer to the given table of differences between cerebrum and cerebellum.

Identify the correct pair of differences.
A. I, II, III and V only
B. II, III and V only
C. I, III and IV only
D. II, III, IV and VI only
Answer : A

Question. Which of the following organisms are secondary consumers in the given food web?

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

Question. Refer to the given diagram of a human heart.

Which of the following options correctly identifies the vessels which carry oxygenated and deoxygenated blood?
Oxygenated blood      Deoxygenated blood
A. X and Z                              Y
B. X and Y                              Z
C. Y and Z                              X
D. Y                                  X and Z
Answer : C

ACHIEVERS SECTION

Question. Which of the following correctly represents the variation of heat energy (H) produced in a metallic conductor in a given time as a function of potential difference (V) across the conductor?
(Assume resistance of the conductor is constant.)

Answer : D

Direction (Q. No. a and b) : Read the given passage and answer the following questions.
The given table shows the positions of six elements P, Q, R, S, T and U in the periodic table

Question a. Identify the elements which form ionic compounds (i) and the elements which form covalent compounds (ii).
    (i)   (ii)
A. S      T
B. T      S
C. R      T
D. P      U
Answer : A

Question b. Select the incorrect statement.
A. Element Q is a non-metal having valency 2.
B. Element P is a metal having valency 2.
C. Elements S and Q combine to form S₂Q type of compound.
D. Elements T and Q combine to form T₃Q type of compound.
Answer : D

Question. Read the following statements about

the given diagram carefully and select the correct ones?
(i) P carries urine and sperms.
(ii) Q secretes a fluid that helps in the lubrication of penis. 
(iii) S produces testosterone but not sperms.
(iv) R secretes fluid that contains nutrients like fructose.
A. (i) and (ii) only
B. (ii) and (iii) only
C. (ii) and (iv) only
D. (i) and (iv) only
Answer : C

Question. Refer to the given paragraph where few words have been italicised and select the correct option.
When food is masticated in mouth it turns into chyme which is then passed on to the stomach where it is churned by strong muscles of stomach. Stomach secretes gastric juice which contains hydrochloric acid, mucus, pepsin and trypsin. Churning by stomach helps to mix food components with gastric secretion. Then, food changes into bolus. Pepsin helps to convert proteins into amino acids. HCl helps to kill bacteria and makes the medium acidic for activation of trypsin.
A. Both mucus and trypsin should not be replaced as they are correctly mentioned.
B. Amino acids should be replaced with fatty acids.
C. Trypsin should be replaced with ptyalin.
D. Positions of chyme and bolus should be interchanged
Answer : D