CBSE Class 10 Science NSO Olympiad MCQs with Answers Set I

LOGICAL REASONING

Question. If it is possible to make only one meaningful English word with the 1st, 6th, 9th and 11th letters of the word ‘QUALIFICATION’, then which of the following will be the 3rd letter of that word? If more than one such word can be formed, give ‘M’ as the answer and if no such word can be formed, give ‘N’ as the answer.
A. A
B. I
C. N
D. M
Answer : C

Question. Find the number of triangles formed in the given figure.

A. 28
B. 32
C. 26
D. None of these
Answer : D

Question. Some letters are coded as given below

What is the code for AEIMVH?
A. 42@#7$
B. 42@47$
C. #2@47$
D. 48@#78
Answer : A

Question. Select the correct mirror image of the given figure

Answer : A

Question. Find the odd one out.
A. NQUZ
B. FIMR
C. HKOT
D. BEIO
Answer : D

Question. Select a figure from the options which is exactly embedded in the given figure as one of its parts.

Answer : A

Question. Eight friends A, B, C, D, E, F, G and H are sitting in a circle facing the centre, not necessarily in the same order. D sits third to the left of A. E sits to the immediate right of A. B is third to the left of D. G is second to the right of B. C is neighbour of B. C is third to the left of H. Who are the neighbours of G?
A. C and A
B. A and F
C. D and C
D. D and F
Answer : C

Question. In the 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 a two-digit even number is followed by another even number, the first one is to be divided by the second one.
(ii) If an even number is followed by a prime number, the two are to be multiplied.
(iii) If an odd number is followed by another odd number, the two are to be added.
(iv) If a three-digit number is followed by a two-digit number which is a perfect square, the second number is to be subtracted from the first number.
(v) If a three-digit number is followed by a two-digit number which is not a perfect square, the first number is to be divided by the second one.
                    24 7 81
                    x 27 57
If ‘x’ and ‘y’ are the resultant of the first row and second row respectively, then y × y = _______ .
A. 4
B. 2
C. 6
D. 8
Answer : A

Question. Select the box that is similar to the box formed, when the given sheet is folded.

Answer : B

Question. In the given Venn diagram, which of the following represents the uneducated women, who are government employees but not urban?

A. 9
B. 10
C. 6
D. 13
Answer : D

SCIENCE

Question. Three identical bulbs connected in series across a source consume 20 W power. If the bulbs are connected in parallel to the same source, the power consumed is
A. 20 W
B. 60 W
C. 90 W
D. 180 W
Answer : D

Question. Which of the following statements is/are correct regarding the given figure?

I. Current I drawn from the battery is 7.5 mA.
II. The potential difference across R_L is 18 V.
A. I only
B. II only
C. I and II
D. None of these
Answer : A

Question. A ray of light is incident at an angle i on a glass slab of refractive index m. If the angle between reflected and refracted light is 90°, then the relationship between i and m is
A. i = tan⁻¹ (1/μ)
B. tan i = μ
C. sin i = μ
D. cos i = μ
Answer : B

Question. A light ray travels in a liquid, through gas bubble and goes into the liquid again as shown in the figure.

Answer : B

Question. A person needs a lens of power 2.5 D for correction of her vision. Then
(i) focal length of the lens is 40 cm.
(ii) focal length of the lens is – 40 cm.
(iii) nature of the lens is concave.
(iv) nature of the lens is convex.
(v) she is suffering from myopia.
A. Only (i) and (iv) are correct.
B. Only (ii) and (iii) are correct.
C. Only (i), (iii) and (v) are correct.
D. Only (i) and (v) are correct.
Answer : A

Question. PQ and RS are long parallel current carrying conductors separated by a certain distance. M is the midpoint between them (see the figure).

The net magnetic field at M is B. Now, the current in the wire PQ is switched off. The magnitude of magnetic field at M becomes
A. 2B
B. B
C. B/2
D. 3B
Answer : B

Question. Which of the following statements is/are correct?
I. During nuclear fission, mass is transformed into energy.
II. Propane is important constituent of natural gas.
III. The main component of LPG is butane.
A. I only
B. III only
C. I and III only
D. II and III only
Answer : C

Question. A shell of mass 5M, acted upon by no external force and initially at rest, bursts into three fragments of masses M, 2M and 2M respectively. The first two fragments move in opposite directions with velocities of magnitudes 2v and v respectively. The third fragment will
A. Move with a velocity v in a direction perpendicular to the other two
B. Move with a velocity 2v in the direction of velocity of the first fragment
C. Be at rest
D. Move with a velocity v in the direction of velocity of the second fragment.
Answer : C

Question. A car covers one-third of its journey with speed v1, next one third with speed v2 and the last one-third with speed v3. The average speed of the body during the entire journey is

Answer : B

Question. At a place, value of acceleration due to gravity g is reduced by 2% of its value on the surface of the earth (Radius of earth = 6400 km). The place is
A. 64 km below the surface of the earth
B. 64 km above the surface of the earth
C. 32 km above the surface of the earth
D. 32 km below the surface of the earth.
Answer : B

Question. A boy stands between the two walls and claps his hands as shown in the figure. If x is less than 60 m and the time between the first and the second echo is 0.25 s, then find the value of x. Velocity of sound in air is 344 m s^–1.

A. 17 m
B. 25 m
C. 29 m
D. 35 m
Answer : A

Question. Read the given statements and select the correct option.
Statement 1 : If a light body and a heavy body possess the same kinetic energy, then the heavy body will possess more momentum.
Statement 2 : Work done by all the forces on a body is equal to change in its kinetic energy.
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. Geetika took four test tubes I, II, III and IV, each containing 10 mL of different solutions. Then different substances are added to each test tube as shown in the figure and shaken well.

Read the given statements carefully and select the incorrect one.
A. The order of pH of the given solutions is III > IV > II > I.
B. Drops of phenolphthalein remain colourless in test tubes I and IV.
C. Methyl orange indicator turns red in test tubes II and III.
D. Both A and C.
Answer : D

Question. The given apparatus is used to study the diffusion of a few gases at the same temperature and pressure.

In which of the following pairs, gases would diffuse into the vacuum with different speeds?
I. CO and SO₂ II. CO and N₂
III. NH₃ and N₂ IV. CO₂ and CH₄
(Given : Atomic mass of H = 1 u, C = 12 u, N = 14 u,
S = 32 u, O = 16 u)
A. I, III and IV only
B. I and IV only
C. II only
D. I, II, III and IV
Answer : A

Question. Match column I with column II and select the correct option from the given codes

A. P-(iv), Q-(i), R-(ii), S-(iii)
B. P-(iii), Q-(ii), R-(i), S-(iv)
C. P-(iii), Q-(i), R-(ii), S-(iv)
D. P-(iv), Q-(iii), R-(i), S-(ii)
Answer : D

Question. Ankur has 32 g of ozone, Nishant has 0.5 mole of P₄ while Rashmi has 6.023 × 10²³ molecules of N₂.
Which of the following is the correct order of number of electrons they have?
A. Rashmi < Ankur < Nishant
B. Nishant > Rashmi > Ankur
C. Rashmi > Ankur > Nishant
D. Ankur < Nishant < Rashmi
Answer : A

Question. Read the given flow chart carefully.

Select the correct statement.
A. An alloy of metal present in ‘X’ is used for soldering purposes.
B. Colourless gas ‘P’ is nitric oxide.
C. Metal oxide ‘Y’ produced is of yellowish brown colour.
D. Both A and C
Answer : D

Question. Solubility of two substances, I and II at 45°C and 80°C is given in the following table

If the temperature of solutions X and Y is dropped to 45°C, then amount of substance I and substance II crystallised out will be respectively
A. 120 g and 90 g
B. 30 g and 10 g
C. 30 g and 0 g
D. 10 g and 30 g
Answer : C

Question. Read the given statements and select the correct option.
Statement 1 : Reactivity of aluminium decreases when it is dipped in nitric acid.
Statement 2 : A protective layer of aluminium nitrate gets formed on the surface of aluminium which stops the further reaction.
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 and statement 2 is false.
D. Both statements 1 and 2 are false.
Answer : C

Question. Schematic atomic structures of four different elements ¹⁶₈W^2–, ²⁰₁₀X, ³⁵₁₇Y– and ²³₁₁Z⁺ are given as I, II, III and IV respectively as follows :

The correct representations are
A. I, II and IV only
B. I, III and IV only
C. III and IV only
D. I and IV only
Answer : D

Question. Which of the following is not correctly matched?
A. Non-metallic character : F > N > C > B > Si
B. Electronegativity : Si > P > C > N
C. Atomic radius : F < O < C < Cl < Br
D. None of these
Answer : B

Question. Three students Renu, Manish and Raj were given three unknown liquids P, Q and R respectively during the lab activity.

On the basis of these properties, which student has chosen the correct separation technique to separate the substance from substance‑water mixture?
A. Renu – Simple distillation
B. Manish – Separating funnel
C. Raj – Fractional distillation
D. All of these
Answer : D

Question. One mole of a hydrocarbon ‘P’ on complete combustion produces CO₂ and H₂O in the molar ratio 1 : 1. The succeeding homologue of ‘P’ is ‘Q’ while preceding homologue is ‘O’. The name of the homologous series is ‘R’. Identify O, P, Q and R.
         O          P         Q         R
A. Ethane Propane Butane Alkane
B. Hexene Pentene Butene Alkene
C. Ethyne Propyne Butyne Alkyne
D. Ethene Propene Butene Alkene
Answer : D

Question. Observe the given reaction carefully and identify (i), (ii), (iii) and (iv).

Answer : C

Question. Which of the following events do not occur during the light reaction of photosynthesis?
I. Photolysis of water
II. Reduction of NADPH to NADP+
III. Evolution of molecular oxygen
IV. Synthesis of assimilatory power
V. Conversion of carbon dioxide to carbohydrates
A. I and II only
B. II and V only
C. II, III and V only
D. I, III and IV only
Answer : B

Question. Which of the following is correct regarding the effects of sympathetic and parasympathetic nervous system as shown in the given table?

A. I, III and V only
B. III and IV only
C. I, IV and V only
D. I, II and V only
Answer : D

Question. Identify the plant hormone ‘X’ from the given statements and select the correct option regarding it.
I. It promotes cell division in plants.
II. It helps in breaking dormancy of seeds.
III. It delays the ageing in leaves.
IV. It brings about morphogenesis along withauxin  during tissue culture.
A. ‘X’ could be gibberellin that also causes bolting in rosette plants.
B. ‘X’ could be ethylene that also promotes yellowing of leaves.
C. ‘X’ could be abscisic acid that causes closure of stomata during desiccation and other stresses.
D. ‘X’ could be cytokinin that increases shelf life ofveg etables.
Answer : D

Question. The genotype for the height of an organism is Tt. What conclusion can be drawn from this?
A. The allele for height has at least two different genes.
B. There are at least two different alleles for the gene controlling height.
C. There are two different genes for height, each having a single allele.
D. There is one allele for height with two different forms.
Answer : B

Question. Which of the following options shows a likely food chain represented by the given pyramid of number?

A. Phytoplankton → Zooplankton → Shellfish → Fish → Shark
B. Maize → Rat → Snake → Meerkat → Lion
C. Tree → Aphid → Ladybug → Bird → Hawk
D. Cyanobacteria → Shrimp → Fish → Kingfisher → Snake
Answer : C

Question. Which of the following activities will help to sustain environmental balance?
(i) Usage of platinum jewellery as it will reduce the load on gold mines.
(ii) Farming as it helps to ensure that man does not eat up all the food producers.
(iii) Use of jute bags instead of polybags.
(iv) Using solar energy as it provides an alternative to fossil fuels.
A. (ii), (iii) and (iv) only
B. (i), (ii) and (iv) only
C. (ii) and (iv) only
D. (iii) only
Answer : A

Question. Which among the following are the artificial ecosystems?
(i) Estuaries (ii) Mountains
(iii) Crop fields (iv) Grasslands
(v) Coral reefs (vi) Parks
(vii) Mangroves (viii) Aquariums
A. (i), (ii) and (v) only
B. (ii), (iv) and (vi) only
C. (iii), (vi) and (viii) only
D. (ii), (vi) and (vii) only
Answer : C

Question. Refer to the given figure and select the correct option regarding functions of X and Y.

             X                                      Y
A. Detoxification             Digestion of foreign particles
B. Cellular respiration     Carbohydrate synthesis
C. Protein synthesis        Glycolipid formation
D. Osmoregulation         Storage of reserve food
Answer : C

Question. Which statement is incorrect for the tissue shown in the given figure?

A. The tissue is usually covered by tough fibrous membrane called perichondrium.
B. The cell embedded in the matrix of this tissue are called chondroblasts.
C. It is found in nose tip, ear pinna, etc.
D. The matrix is highly calcified and is richly supplied with nerves and blood vessels.
Answer : D

Question. Identify incorrect differences between dicots and monocots from the given table

A. I, II and III only
B. II, III and V only
C. III and IV only
D. I, III and V only
Answer : C

Question. Refer to the given Venn diagram and select the correct option regarding P and Q.

A. P could be small pox whereas Q could be diphtheria.
B. P could be AIDS whereas Q could be malaria.
C. P could be common cold whereas Q could be whooping cough.
D. P could be typhoid whereas Q could be plague.
Answer : A

ACHIEVERS SECTION

Direction (Q. No. a and b) : Read the given passage and answer the following questions.
The electronic arrangements of four atoms of elements P, Q, R and S are given as follows

Question a. The elements that belong to same period (i) and the elements that belong to same group (ii) of the periodic table are
          (i)           (ii)
A. Q and S  R and S
B. P and Q  R and S
C. R and S  Q and S
D. Q and R  P and S
Answer : C

Question b. Select the correct statement from the following.
A. Element P has least metallic character.
B. The atomic size of S is greater than that of P.
C. Element S is more electronegative than Q.
D. R is a reactive gas.
Answer : C

Question. Identify P, Q, R and S in the given flow chart and select the correct option regarding them.

A. P could be copper-T that prevents ovulation and implantation in the uterus.
B. Q could be femidom which is used by females just before coitus
C. R could be oral pills that contain LH and FSH to prevent ovulation.
D. S could be tubectomy that involves removal of a small portion of sperm duct surgically
Answer : B

Question. A time varying current I is passed through a resistance R as shown in figure.

Which of the following statements is/are correct?
I. Average current through the resistance is (11/2)I₀.
II. The heat generated in the resistance during time interval t₀ to 3t₀ is 10I²₀ Rt₀.
III. Total charge flown through the resistance is 11/2 I₀ t₀.
A. I only
B. II only
C. II and III only
D. I, II and III.
Answer : C

Question. Refer to the given figure and select the incorrect option regarding L-O.

A. Secretion of L helps in lubrication and swallowing of food, while exocrine part of N secretes alkaline juice with pH value around 8.
B. Juice stored in M contains no enzyme but activates the enzyme lipase, while O converts some toxic substances into harmless substances.
C. If N is removed surgically in a person, it will not affect the digestion process as digestive juices from O and M will compensate for the same.
D. Enzyme of L helps in digestion of carbohydrates, while secretion of N helps in the digestion of carbohydrates, proteins and fats.
Answer : C