CBSE Class 10 Science NSO Olympiad MCQs with Answers Set E

Logical Reasoning

Question. A word-number arrangement machine, when given a particular input, rearranges it following a particular rule. The following is the illustration of the input and the steps of arrangement.
Input: huge elephant 39 dog 57 42 small 23
Step I: small huge elephant 39 dog 57 42 23
Step II: small 23 huge elephant 39 dog 57 42
Step III: small 23 huge 39 elephant dog 57 42
Step IV: small 23 huge 39 elephant 42 dog 57 
Step IV is the last step of the given input.
As per the rule followed in the above steps which is the last step for the given below input?
Input: Mission impossible 2 13 7 Oscar winner 19.
A. IV
B. V
C. VI
D. VII
Answer : B

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

Question. Choose the correct mirror image of Fig. (X), if mirror is placed vertically to the left.

Answer : D

Question. M is sister of K. D is brother of K. F is mother of M.
How is K related to F?
A. Son
B. Daughter
C. Son or Daughter
D. Wife
Answer : C

Question. A, B, C, D, E, F, G and H are sitting around a circular table facing the centre. A sits second to the left of D, who is third to the left of E. C sits third to the right of G, who is not an immediate neighbour of E.
H sits third to the right of B, who sits second to the right of G.
What is the position of A with respect to E?
A. Third to the left
B. Third to the right
C. Second to the left
D. Second to the right
Answer : B

Question. A set of three figures X, Y and Z showing a sequence of folding of a piece of paper is given. Fig. (Z) 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. (Z).

Answer : B

Question. The six faces of a cube are colored black, brown, green, red, white and blue, such that
(i) Red is opposite to black.
(ii) Green is between red and black.
(iii) Blue is adjacent to white.
(iv) Brown is adjacent to blue.
Which of the following colors is opposite to white?
A. Black
B. Blue
C. Brown
D. Green
Answer : C

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 multiplied.
(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 a perfect square, then 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 one.
                                  10 15 5
                                  14 11 p
If p is the resultant of the first row, what will be the resultant of the second row?
A. 6
B. 81
C. 5
D. 24
Answer : C

Question. The following letters are coded as follows:
Letter: F P M R E K D A I H T U J W
Digit/Symbol: 6 5 4 * 8 1 2 © 7 3 $ @ % 9
While coding the given letters following conditions are also to be observed. 
Conditions:
(i) If the first letter is a consonant and the last letter is a vowel, their codes are to be interchanged.
(ii) If both the first and the last letters are vowels, both are to be coded as the code for the last letter.
(iii) If both the first and the last letters are consonants, both are to be coded as the code for the first letter.
HMUIWA
A. 34@79©
B. 34@793
C. ©4@79©
D. ©4@793
Answer : D

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

Answer : A

Science

Question. The given figure shows a focal length and centre of curvature of the lens are marked along with four random points, P, Q, R and S.
Which of the following set of points correctly represents the position of object and corresponding position of image?

    Position of object    Position of image
A.             P                                R
B.             Q                               S
C.             P                               S
D.             Q                               P
Answer : D

Question. Two resistance wires of the same material and of equal lengths and equal diameters are connected in series in a simple electric circuit consisting of a voltage source of voltage V. Now, the same wires are connected in parallel in the same circuit for the same time but voltage source is replaced by another voltage source of voltage 2V. The ratio of heat produced in the two cases is
A. 1 : 1
B. 1 : 4
C. 1 : 8
D. 1 : 16
Answer : D

Question. A train starting from rest at one station, accelerates uniformly and attains a speed v after sometime.
After travelling at this speed for sometime, it retards uniformly and stops at the next station. If R be the uniform resistance of the given track and the duration of the uniform motion is just half the total journey time, the average power supplied by the train engine is
A. vR/2
B. 3vR/2
C. 3vR/4
D. vR/4 

Answer : C

Question. Two plane mirrors are inclined to each other at some angle. A ray of light is incident on one of them at an angle of 35°. The light after reflection falls on the second mirror and gets reversed. The angle between the mirrors is
A. 17.5°
B. 35°
C. 52.5°
D. 70°
Answer : B

Question. Two identical spheres of radius R, made of a material of density r, are in contact with each other. If the gravitational attraction between them is F, then

Answer : B

Question. A bar magnet is rotated on a shaft near to a coil which is connected to a resistor of resistance R as shown in the figure.

Which of the following changes does not increase the induced current in the coil?
A. Moving the magnet closer to the coil.
B. Turning the magnet in the opposite direction at the same speed.
C. Turning the magnet in the opposite direction at a greater speed.
D. Using a coil with more turns.
Answer : B

Question. Read the given statements and select the correct option.
Statement 1 : 1 atomic mass unit is equivalent to about 931 mega electron volts of energy.
Statement 2 : 1 electron volt = 1.602 × 10^–13 joule
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. A body is thrown vertically upward in air and air resistance is taken into account. The time of ascent is t₁ and time of descent is t₂, then which of the following is true ?
A. t₁ = t₂
B. t₁ > t₂
C. t₁ < t₂
D. Cannot be predicted
Answer : C

Question. A dish of mass 10 g is kept floating horizontally in air by firing bullets, each of mass 5 g, with the same velocity, at the rate of 10 bullets per second and the bullets rebound with the same speed in opposite directions. The velocity of each bullet at the time of impact is (Take g = 10 m s^–2)
A. 1 m s^–1
B. 5 m s^–1
C. 10 m s^–1
D. 100 m s^–1
Answer : A

Question. Which of the following statements is/are correct ?
(i) The ratio of the speed of light to the speed of sound is called the Mach number.
(ii) Speed of sound increases with increase in temperature.
(iii) For hearing a distinct echo, the minimum distance of the obstacle from the source of sound should be 34.4 m.
(iv) Wavelength of sound audible to human lies between 17 mm to 17 m.
A. (iii) only
B. (ii) and (iv) only
C. (i), (iii) and (iv) only
D. (i), (ii), (iii) and (iv)
Answer : B

Question. In the given circuit, the total current supplied by the battery is

A. 1 A
B. 2 A
C. 3 A
D. 6 A
Answer : C

Question. A long-sighted person cannot see objects clearly at a distance less than 40 cm from his eye.
The power of the lens needed to read an object at 25 cm is
A. –2.5 D
B. +2.5 D
C. – 6.25 D
D. +1.5 D
Answer : D

Question. The given diagram shows the energy levels of the reactants and products for a particular reaction :
Which of the following processes can be related to the given diagram?

A. Ethyne gas burns in oxygen to form carbon dioxide and water along with evolution of heat.
B. When solid mercury (II) oxide is heated liquid mercury and oxygen gas are produced.
C. Hydrogen gas combines with chlorine gas in the presence of light to form hydrogen chloride gas.
D. Potassium chlorate decomposes in presence of heat to form potassium chloride and oxygen.
Answer : A

Question. Which of the following statements are correct?
I. Solubility of solids in liquids usually decreases with decrease in temperature and the extra amount of solute crystallises out.
II. The solubility of gases in liquids increases on increasing the temperature.
III. Solubility of gases in liquids increases on increasing the pressure.
IV. While expressing the solubility of a substance temperature is not specified.
A. I and III only
B. II and III only
C. I, II and IV only
D. III and IV only
Answer : A

Question. The given table shows a part of the periodic table.

P, Q, R, T and U are respectively
A. Mg, S, Ar, Al, and Ne
B. O, Mg, Ar, P and Ne
C. Mg, O, Ne, P and Ar
D. O, Mg, Ne, P and Ar
Answer : C

Question. Observe the given graph carefully and find the relative atomic mass of the isotopes

A. 27.86 u
B. 13.99 u
C. 14.86 u
D. 15.98 u
Answer : B

Question. Daivik, a class 10 student studied the reaction between a carbonate and an acid ,in the lab. His results are shown in the given graph

Answer : B

Question. 8 g of E₂O₃ contains 5.6 g of ‘E’. How many moles of E does 16.8 g of the element ‘E’ contain?
A. 0.1
B. 0.2
C. 0.3
D. 0.75
Answer : C

Question. In an experiment, 5 cm³ of 1.0 mol/dm³ NaOH solution is gradually added to 10 cm³ of 1.0 mol/dm³ HCl solution containing methyl orange indicator.

Which of the following changes will occur in the mixture?
A. pH of the resultant solution increases.
B. The methyl orange indicator changes colour from red to yellow.
C. Number of moles of water decreases and beaker gets warmed up.
D. A precipitate is formed.
Answer : A

Question. The electronic configuration of an ion Z^2– is 2, 8.
If the number of neutrons present in the parent atom ‘Z’ is 11 then the nucleon number of ‘Z’ is
A. 16
B. 19
C. 20
D. 21
Answer : B

Question. The given diagram shows the arrangement of valence electrons in organic compound Q, having molecular formula X₂YZ₂.

What could be the compound Q?
A. Methanol
B. Ethanol
C. Methanoic acid
D. Ethanoic acid
Answer : C

Question. Some properties of substances P, Q, R and S are given in the table :

Which of the given substances represents a gaseous non-metal at room temperature?
A. P
B. R
C. Q
D. S
Answer : B

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

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

Question. Ms. Neelam, a class 10 teacher took Cu, Al, Pb and Zn strips respectively in four test tubes labelled as I, II, III and IV and added 10 mL of freshly prepared ferrous sulphate solution to each test tube as shown in the figure

Black residue would be obtained in test tubes
A. I and II only
B. I and III only
C. II and III only
D. II and IV only.
Answer : D

Question. Refer to the given table and select the incorrect statement regarding organelles X and Y.

A. Organelle X arises from joint activity of endoplasmic reticulum and organelle Y.
B. The membrane and hydrolytic enzymes of X are synthesised in Y
C. Organelle X is abundant in leucocytes and macrophages whereas it is absent in mammalian red blood corpuscles.
D. If organelle Y is absent in tadpole of frog then it will never metamorphose into an adult frog.
Answer : B

Question. Shown below is the diagrammatic representation of an animal tissue, X.

Which of the following holds true regarding this tissue?
A. Tissue X is abundantly present in fat bodies of frog and blubber of whale.
B. Tissue X is a type of dense connective tissue.
C. Tissue X fills the spaces inside many organs and is commonly called packaging tissue of body.
D. Tissue X is very strong and non-flexible vertebrate tissue.
Answer : C

Question. Ritu was suffering from high fever for many days.
Doctor advised her some antipyretic which she took according to the prescribed doses. Her temperature went down to normal but reoccurrence of fever continued.
Doctor then advised Ritu to get her blood test done to rule out the presence of some antibodies and then gave her medications accordingly. She recovered soon.
The given graphs show the result of her blood tests during illness (graph I) and after recovery (graph II).

What could be inferred from the given graphs?
A. Ritu suffered from three kinds of pathogenic infections simultaneously.
B. This time Ritu suffered only from that pathogenic infection for which her body produced antibody Q.
C. Ritu might be vaccinated or had contracted the actual diseases in her life for which her body produced antibodies P and R.
D. Both B and C
Answer : D

Question. Refer to the given figure showing three different organisms P, Q and R.
Select the correct statement(s) regarding these organisms.

(i) Organism Q has true coelom whereas organisms P and R are pseudocoelomates.
(ii) Organisms P and R are diploblastic whereas organism Q is triploblastic.
(iii) Bodies of organisms P and Q are metamerically segmented.
(iv) Organism Q bears special paired locomotory appendages called parapodia however in organism R tube feet helps in locomotion.
(v) Excretion in organisms P and Q takes place by flame cells and nephridia respectively.
A. (ii) and (iii) only
B. (v) only
C. (iv) and (v) only
D. (i) only
Answer : B

Question. Whi ch of the following is true in case of intercropping?
(i) Crops are grown in definite pattern of rows.
(ii) Fertilisers cannot be applied easily to different crops.
(iii) Crops can be harvested and threshed separately.
(iv) Spraying of pesticides for separate crops is not possible.
(v) Seeds are mixed before sowing.
A. (i), (iv) and (v) only
B. (i) and (iii) only
C. (iii) and (v) only
D. (iv) and (v) only
Answer : B

Question. Which of the following statements are incorrect about vegetative propagation in plants?
(i) It makes possible the propagation of some seedless fruit plants like banana, etc.
(ii) It is the means to produce genetically identical offspring.
(iii) It makes plants more adaptable to the changing environmental conditions.
(iv) Vegetative propagation by plant tissue culture can be used for the production of disease-free plants.
(v) It brings adequate dispersal of vegetative propagules and thus reduces over-crowding.
A. (ii) and (iv) only
B. (ii), (iv) and (v) only
C. (i), (iii) and (iv) only
D. (iii) and (v) only
Answer : D

Question. Some humans are able to roll their tongue, while others are not. Two parents (both tongue-rollers) have four children, all of whom are not tongue-rollers. Which of the following statements hold true regarding this?
(i) The allele for tongue-rolling is dominant.
(ii) The probability that their next child will be a tongue-roller is 0.5.
(iii) The probability that their next child will not be a tongue roller is 0.75.
(iv) Both parents have one allele for tongue-rolling and one allele for non-tongue-rolling.
A. (i) and (iii) only
B. (i) and (iv) only
C. (ii) and (iii) only
D. (ii) and (iv) only
Answer : B

Question. Refer to the given illustration.

What could be inferred from the process illustrated above?
A. The given process illustrates speciation through genetic drift. 
B. The given process illustrates speciation through reproductive isolation.
C. The given process depicts an example of natural selection.
D. The given process depicts an example of artificial selection.
Answer : A

Question. The given diagram shows a normal 28 day menstrual cycle in a human female.

Select the correct statement regarding this.
A. The hormone secreted in large amounts in phase III is also responsible for maintaining pregnancy in human females.
B. Primary follicle of ovary matures into Graafian follicle in phase II.
C. Corpus luteum secretes progesterone in phase I however it degenerates completely in phase III.
D. Both A and B
Answer : D

Question. Read the given paragraph.
Photosynthesis in plants consists of two phases: 
X and Y. Phase X requires light energy and occurs in granum of chloroplast whereas phase Y is light independent and occurs in stroma of chloroplast.
Which of the following holds true regarding phases
X and Y of photosynthesis?
A. In phase X, light energy is used up in photolysis of water and molecular oxygen is evolved.
B. In phase Y, electrons and protons are used up in synthesis of assimilatory power.
C. Assimilatory power generated in phase Y is used up in phase X to convert CO₂ into carbohydrates.
D. Phase X utilises carbon dioxide gas of atmosphere whereas phase Y evolves oxygen gas that escapes into atmosphere.'
Answer : A

Question. Refer to the given food chain operating in an aquatic ecosystem.

When a new species X was introduced into this community, the population of platy fish rose and population of catfish fell over subsequent two weeks. Species X is most likely to be
A. Another herbivore like platy fish
B. A predator of Daphnia only
C. A predator of catfish only
D. A predator of platy fish and prey of shark .
Answer : C

Achievers Section

Question. The given figure shows the I-V curve (i) for a nichrome wire of fixed length and cross-section.

A. Increase the length of nichrome wire.
B. Decrease the thickness of nichrome wire.
C. Replace the nichrome wire with a similar copper wire.
D. None of these.
Answer : C

Direction: Refer to the given paragraph and answer the questions a and b.
An organic compound ‘A’ on heating with concentrated H₂SO₄ forms a compound ‘B’ which on addition of one mole of hydrogen in presence of Ni forms a compound ‘C’.
One mole of compound ‘C’ on combustion forms two moles of CO₂ and three moles of H₂O.

Question a. Which of the following represents the compound ‘C’?
A. C₂H₆, a saturated hydrocarbon
B. C₂H₄, an unsaturated hydrocarbon
C. HCOOH, an unsaturated acid
D. C₂H₅OH, a saturated alcohol
Answer : A

Question b. When ‘B’ and ‘C’ are added separately to the test tubes containing orange-brown liquid ‘X’, the colour disappears in case of ‘B’ but remains same in case of ‘C’. The name of the liquid ‘X’ and the substance responsible for colour change are respectively
A. Alkaline KMnO₄ solution and ethanoic acid
B. Alkaline KMnO₄ and ethanol
C. Bromine water and 1, 2-dibromoethane
D. Bromine water and 1, 1, 2, 2-tetrabromoethane.
Answer : C

Question. The given diagram shows a congenital defect in which the ventricular septum of the human heart fails to form fully resulting in a 'hole in the heart'.

Which of the following would not be a likely consequence of this disease?
A. A reduction in the pressure of blood leaving through the aorta
B. A reduction in the percentage of oxygenated blood in the aorta
C. A reduction in the amount of oxygen brought to body cells
D. A reduction in the pressure of blood entering the lungs.
Answer : D

Question. Read the given statements each with one, two or three blanks and select the option that correctly fills any four of these.
(i) An ecological pyramid of numbers is upright in P ecosystem and inverted in Q food chain.
(ii) Pyramid of biomass is upright in R and inverted in S ecosystem.
(iii) Gases like CO₂ allow the T wave heat radiations of sun to reach the earth's surface but do not allow the U wave heat radiations reemitted by earth to escape, thereby causing V flux.
(iv) Large amount of W is added to the atmosphere by marshes, paddy fields and biogas plants.
A. P-Grassland, Q-Aquatic, T-Long, W-Sulphur dioxide
B. Q-Parasitic, S-Pond, U-Long, W-Methane
C. Q-Detritus, R-Pond, V-Greenhouse, W-Chlorofluorocarbon
D. P-Parasitic, T-Short, U-Long, W-Carbon monoxide
Answer : B