CBSE Class 8 Science NSO Olympiad MCQs with Answers Set H

LOGICAL REASONING

Question. Find the odd one out.

Answer : C

Question. Three positions of a dice are shown. When 3 is at the bottom, which number will be on the top?

A. 4
B. 2
C. 5
D. 6
Answer : A

Question. All the letters which occur at odd places in the word EXCITEMENT are placed at odd places such as first letter is placed at third place, third letter at fifth place and so on. Similarly, the letters at even places are placed. Last two letters i.e., letter at odd place is placed at first place and letter at even place is placed at second place. Now, which of the following letters will be seventh from the right end in the new arrangement?
A. T
B. E
C. X
D. M
Answer : C

Question. Which of the following figures will complete the pattern given in Fig. (X)?

Answer : A

Question. If P $ Q means P is the father of Q, P # Q means P is the mother of Q and P * Q means P is the sister of Q, then N # L $ P * Q shows Q is ______ of N.
A. Nephew
B. Grandson
C. Granddaughter
D. Data inadequate
Answer : D

Question. Find the water image of given combination of letters/ numbers/symbols.

Answer : A

Question. Which of the following Venn diagrams best depicts the relationship amongst, "Paddy, Wheat and Rabi-Crop"?

Answer : C

Question. Which of the following indicates similar relationship as 'NORMAL' has with 'LMPOCN'?
A. RESCUE : PCQAWG
B. BRANCH : DTCLAF
C. NATION : LYRGMK
D. FRIEND : DPGGPF
Answer : D

Question. Group the given figures into three classes on the basis of their identical properties using each figure only once.

A. 1, 2, 3; 5, 7, 8; 4, 6, 9
B. 1, 2, 5; 3, 7, 8; 4, 6, 9
C. 1, 2, 6; 3, 5, 7; 4, 8, 9
D. 1, 3, 5; 2, 7, 9; 4, 6, 8
Answer : B

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 a two digit even number, then they are to be added.
(ii) If an odd number is followed by a two digit odd number, then the first number is to be subtracted from the second number.
(iii) If an even number is followed by a number which is a perfect square of a number, then the second number is to be divided by the first number.
(iv) If an even number is followed by a two digit even number, then the first number is to be multiplied by the second number.
4      12    144
7      18     45
What is the product of the resultant numbers of both the rows?
A. 60
B. 80
C. 40
D. 90
Answer : A

SCIENCE

Question. The given diagrams show three different circuits. In each circuit, similar batteries and bulbs of the same wattage are used. When the electric circuits are connected, all the bulbs light up.

Which of the following options is true about the bulbs 1, 2 and 3?
      Bright    Brighter   Brightest
A.       1              2              3
B.       3              2              1
C.       2              3              1
D.       2              1              3
Answer : B

Question. Read the given statements and select the correct option.
Statement 1 : When deep-sea fish are brought to the surface of the sea, their bodies burst.
Statement 2 : Blood in the blood vessels of the deep-sea fish flows at very high pressure.
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 : A

Question. The given graph shows the change in temperature of water with time as it is brought to boil before being left to cool.
Based on the graph, which of the following statements are correct?
(i) Evaporation only occurs from P to Q.
(ii) There is heat gain from P to R.
(iii) The water is boiled for 6 minutes.
(iv) Water exists in two different states between Q and R.

A. (i) and (ii) only
B. (ii) and (iv) only
C. (i) and (iii) only
D. (ii), (iii) and (iv) only
Answer : D

Question. A sound is played on a flute. A sound of same pitch is played on a trumpet. Which of the following correctly compares the two sound waves?
     Frequency              Speed
A. Different                    Different
B. Different                    Same
C. Same                        Different
D. Same                        Same
Answer : D

Question. The ray from a laser pointer hits a plane mirror and the reflected ray strikes a screen. How far away from point X should the ray strike the mirror to cause the reflected ray to hit point R?

A. 6 cm
B. 12 cm
C. 16 cm
D. 18 cm
Answer : C

Question. Read the given statements and select the correct option.
(i) Lightning bolt occurs because air is a good conductor of electricity.
(ii) During lightning it is safe to take shelter under a tree.
(iii) When a comb is run through dry hair, the comb acquires a negative charge.
(iv) When a glass rod is rubbed with silk cloth, glass rod acquires positive charge.
A. (i) and (ii) only
B. (ii) and (iii) only
C. (iii) and (iv) only
D. (i) and (iv) only
Answer : C

Question. Study the displacementtime graph of a toy car given here and choose the correct statement(s) from the following.

A. The toy car is slowest during first 10 seconds.
B. The toy car is slowest in between 10 to 20 seconds.
C. The toy car is fastest during first 10 seconds.
D. Both B and C.
Answer : D

Question. A 100 N uniform rod of length 6L is supported by two forces F₁ and F₂ as shown here. What is the ratio for F₁ to F₂?

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

Question. Which of the following is an incorrect match?

Answer : D

Question. Which of the following statements is/are true?
(i) Rainbow is formed by the refraction of sunlight by tiny droplets of water suspended in the air.
(ii) Apparent bending of a pencil half dipped in water is because of refraction.
(iii) When light ray enters from air to water, it bends towards the normal.
(iv) When two refracting surfaces of the glass slab is kept parallel to each other, the emerging light ray will be parallel to the incident ray.
A. (i) only
B. (ii) and (iii) only
C. (ii), (iii) and (iv) only
D. (iv) only
Answer : C

Question. The diagram shows an isolated sphere X with its charge distribution.
Another similar uncharged earthed sphere Y is brought near sphere X. Which of the following diagrams shows the final charge distribution on both spheres?

Answer : D

Question. A ball rolled on four wooden surfaces of different roughness when a similar push was applied on it. The graph shows the distance travelled by the ball on the surfaces over time.
Which of the following conclusion is/are correct?
(i) Different magnitudes of the friction were produced when the ball was rolling on different wooden surfaces.
(ii) Surface Q is rougher than surface R.
(iii) Surface S has the least roughness.

A. (i) only
B. (ii) only
C. (iii) only
D. (i) and (iii) only
Answer : A

Question. Read the following passage and select the option which correctly fills the blanks.
If a metal wire is connected through a battery then the conventional current in the wire flows from (i)  terminal to (ii) terminal of the battery while the electronic current flows from (iii) terminal to (iv) terminal of the battery.

Answer : B

Question. In an experiment to determine the speed of sound, a student stands 150 m from a wall and claps. When he claps once, what is the time interval between the sound of the clap and its echo heard by the student, in terms of v, the speed of sound?
A. 150 m/v
B. 200 m/v
C. 300 m/v
D. 335m/v
Answer : C

Question. The artificial satellites sent into space by India in ascending order of their launching dates are
A. APPLE, EDUSAT, ROHINI, INSAT 4B
B. EDUSAT, ROHINI, APPLE, INSAT 4B
C. ROHINI, APPLE, EDUSAT, INSAT 4B
D. INSAT 4B, EDUSAT, APPLE, ROHINI.
Answer : C

Question. Read the given passage and fill in the blanks by choosing an appropriate option.
Metals have high densities except (i) which can even float on water. Metals are malleable and ductile. (ii) are the most malleable and ductile metals. All metals conduct heat and electricity. (iii) is the best conductor while (iv) is a poor conductor.

Answer : C

Question. Observe the given experimental set-up carefully and choose the correct statement

A. Solution X is soap solution and solution Y is vinegar.
B. Solution X is nitric acid and solution Y is baking soda.
C. Solution X is carbonic acid and solution Y is sugar solution.
D. None of these
Answer : B

Question. A brief information about a few substances is given as :
X : It is the residue left behind after destructive distillation of coal.
Y : It is a mixture of hydrogen, methane, carbon monoxide and other gases.
Z : It contains several carbon compounds which are used to make pesticides, explosives, synthetic fibres, perfumes, etc.
X, Y and Z are respectively
A. Kerosene, CNG and ammoniacal liquor
B. Bitumen, coal gas and coal tar
C. Coke, coal gas and coal tar
D. Petrol, CNG and bitumen.
Answer : C

Question. A science teacher has arranged a few test tubes as :

Which of the following statements is incorrect about the given experimental set-up?
A. Turmeric solution turns red in test tubes 1 and 3.
B. China rose indicator turns green in test tubes 2 and 4.
C. Methyl orange turns yellow in test tubes 1 and 3.
D. Phenolphthalein remains colourless in test tubes 2 and 4.
Answer : B

Question. Four experimental set-ups are shown in the given figure.

No reaction will take place in beaker(s)
A. II only
B. I and IV only
C. I and II only
D. III and IV only.
Answer : C

Question. Study the given Venn diagram carefully and identify points 1, 2 and 3.

Answer : C

Question. Shreya, a class 8 student listed the properties and uses of a few fibres in the given table

W, X, Y and Z are respectively
A. Rayon, acrylic, polyester and nylon
B. Wool, cotton, nylon and acrylic
C. Polyester, cotton, nylon and rayon
D. Acrylic, polyester, cotton and nylon.
Answer : A

Question. Which of the following statements are correct?
I. Yellow flames are ideal for heating.
II. The substances which vaporise during burning give flames.
III. Luminous zone contains unburnt carbon particles.
IV. The non-luminous zone has the highest temperature.
A. I, II and III only
B. II and IV only
C. II, III and IV only
D. I, III and IV only
Answer : C

Question. Refer to the given ultrastructure of an animal cell. Identify the labelled parts (P–S), match them with their functions and select the correct option. 
(i) Synthesising proteins from amino acids
(ii) Synthesising lipids
(iii) Packaging of materials synthesised in cell
(iv) Secreting digestive enzymes

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

Question. Refer to the given flow chart and select the correct statement regarding P, Q, R, S and T

(i) Q is cellulosic whereas S is proteinaceous in nature.
(ii) S could be obtained from a viviparous animal whereas T could be obtained from an oviparous animal with four stages in its life cycle.
(iii) P and S are non-biodegradable fibres.
(iv) P and R are petroleum based fibres.
(v) Organisms providing S generally inhabit desert lands whereas those providing Q generally inhabit polar regions.
A. (i), (ii) and (iii) only
B. (i) and (ii) only
C. (i), (iv) and (v) only
D. (i), (ii), (iv) and (v) only
Answer : B

Question. Refer to the given Venn diagram. Identify the food components X and Y, and select the incorrect statement regarding them.

A. Excess of X could be stored in the cells of liver.
B. Pancreas secretes digestive juices which acts on Y only.
C. Y could be a food component required for body building and repair of damaged tissues or a food component that cannot be digested properly in the body if liver stops manufacturing bile.
D. Products of digestion of Y could be glycerol and fatty acids.
Answer : B

Question. Refer to the given figure. Identify P – S and select the correct statements regarding them.

(i) If both P are surgically removed from a female's body then she will not menstruate but can still produce eggs.
(ii) R is a very small organ in a female which serves as a site of formation, implantation and further development of zygote.
(iii) When embryo implants and develops in Q, it is removed by medication or invasive surgical procedures as it could be life threatening for mother.
(iv) Labelled part S receives sperms and also serves as birth canal.
A. (iii) and (iv) only
B. (i) and (iv) only
C. (i) and (ii) only
D. (i), (ii) and (iv) only
Answer : A

Question. Refer to the given schematic representation of circulation in humans. Identify X, Y and Z and select the correct statement regarding them.

A. In the absence of Z in body, nutrient uptake by body cells will remain unaffected but elimination of waste from body cells will not take place.
B. Y has no valves while X has valves to prevent backward flow of blood.
C. X is vena cava that carries deoxygenated blood from body parts to the left atrium of heart.
D. Through Y, the medicines reach the heart from where they are pumped all over the body.
Answer : B

Question. Which of the following statements are correct?
(i) Water logging increases the amount of salt in the soil that reduces soil fertility.
(ii) 2, 4-D, MCPA and butachlor are common weedicides.
(iii) Leguminous crops (like pea and beans) cannot be grouped in combination with cereals (like wheat and rice) under mixed cropping as both use large amount of nitrogen from the soil.
(iv) Manures provide specific nutrients to the soil.
(v) Paddy, maize, cotton and groundnut are examples of kharif crops while wheat, gram, pea and mustard are examples of rabi crops.
A. (i), (iv) and (v) only
B. (ii), (iii), (iv) and (v) only
C. (i), (ii) and (v) only
D. (i), (ii), (iii) and (iv) only
Answer : C

Question. Rectify the given statements by replacing the underlined words and select the correct option.
(i) The viscous fluid present in the nucleus is called cytoplasm.
(ii) Vacuoles are rod shaped structures which oxidise food to provide energy.
(iii) Mitochondria contain green pigment chlorophyll and take part in photosynthesis.
(iv) Lysosomes take part in synthesis of proteins.
A. (i)-Nucleoplasm, (ii)-Lysosomes,
(iii)-Plastids, (iv)-Centrosomes
B. (i)-Protoplasm, (ii)-Ribosomes,
(iii)-Centrosomes, (iv)-Golgi bodies
C. (i)-Nucleoplasm, (ii)-Mitochondria,
(iii)-Chloroplasts, (iv)-Ribosomes
D. (i)-Protoplasm, (ii)-Plastids,
(iii)-Chloroplasts, (iv)-Ribosomes
Answer : C

Question. Refer to the given food web and select the correct statement regarding it.
(i) N could be a herbivore whereas O could be an omnivore.
(ii) Stability of this food web will be affected if entire population of organism L is removed from the community where this food web is functional.
(iii) K is a saprophyte which plays an important role in recycling of nutrients.
(iv) There are eight interconnected food chains in the given food web.
(v) N serves as secondary as well as tertiary consumer in the given food web.

A. (i) and (ii) only
B. (ii), (iv) and (v) only
C. (i), (ii), (iii) and (iv) only
D. (i) and (iii) only
Answer : A

Question. Refer to the given list of fruits/seeds.
(i) Hiptage (ii) Acer (iii) Xanthium
(iv) Urena (v) Coconut (vi) Dandelion
(vii) Lotus (viii) Balsam (ix) Pea (x) Guava
Select the option which correctly matches these fruits/seeds with their dispersal agents, wind (P), water (Q), animals (R) and explosion (S).
            P                   Q                     R                  S
A. (i), (ix), (v)      (vii), (viii)       (iii), (iv), (x)       (ii), (vi)
B. (i), (ii), (ix)      (v), (vii)         (iii), (iv), (x)       (vi), (viii)
C. (i), (iii), (viii)    (v), (vii)         (ii), (iv), (x)       (vi), (ix)
D. (i), (ii), (vi)      (v), (vii)         (iii), (iv), (x)       (viii), (ix)
Answer : D

Question. Select the pair of diseases that are caused by contaminated water.
A. Cholera and typhoid
B. Diarrhoea and common cold
C. Pneumonia and typhoid
D. Malaria and pneumonia
Answer : A

Question. Read the given paragraph and select the correct option regarding P, Q, R and S.
According to Red list of International Union for Conservation of Nature (IUCN), P is an extinct animal, Q is an endangered animal, R is a vulnerable animal whereas S is a critically endangered animal.

Answer : B

Question. The period of crop harvesting is celebrated with great joy and happiness in all parts of India. Special festivals are associated with the harvest season. Which among the following group of festivals is associated with harvest season?
A. Pongal, Holi, Diwali, Nabanna
B. Diwali, Christmas, Eid, Pongal
C. Pongal, Eid, Holi, Nabanna
D. Pongal, Baisakhi, Eid, Nabanna
Answer : A

ACHIEVERS SECTION

Direction (Q. No. a and b): Refer to the given passage and answer the following questions.
The given figure shows a plane mirror X placed in front of a torch. A small cardboard piece Y with a hole is illuminated by the torch as shown in the figure.

Question a. At which point should the eye be placed so that the reflected ray from the mirror X can be seen?
A. P
B. Q
C. R
D. S
Answer : B

Question b. If you place a sufficiently long mirror Z perpendicular to mirror X then the angle of reflection for the ray reflected from mirror Z will be
A. 25°
B. 45°
C. 65°
D. 115°
Answer : C

Question. The given figure represents a fractionating column used in refineries.
Which of the following statements are correct?

I. Substance U has the highest boiling point among all the fractions while substance Z has the lowest boiling point.
II. Substance U is used as a domestic fuel while substance Z is used for lubrication.
III. U, V, W and X all are used as fuels.
IV. V is used in power stations while X is used as a fuel for lamps and stoves.
A. I and IV only
B. II and III only
C. I, III and IV only
D. I, II, III and IV
Answer : B

Question. Refer to the given dichotomous key. Identify P –T and select the incorrect statement.
I. (a) It is unicellular organism. – Go to II
(b) It is multicellular organism. – Go to IV
II. (a) It possesses well organised nucleus. – Go to III
(b) It lacks well organised nucleus. – P
III. (a) Nutrition is parasitic. – Q
(b) Nutrition is mixotrophic. – R
IV. (a) It possesses chlorophyll. – S
(b) It lacks chlorophyll. – T
A. P can convert lactose sugar of milk into lactic acid.
B. R could be Euglena which possesses cilia that helps in movement.
C. Q could be Plasmodium which causes malaria or it could be Entamoeba which causes amoebic dysentery in humans.
D. S could be a plant like pondweed whereas T could be a scavenger like vulture or a decomposer like Rhizopus.
Answer : B

Question. Refer to the given graph representing the blood glucose concentration of two persons X and Y after eating a meal.
[Note : Both persons X and Y are not under any medication.]

Select the incorrect statement(s) regarding blood glucose concentration in both the persons X and Y.
(i) Both persons X and Y had insulin released into their blood stream by their pancreas after the meal.
(ii) Person X is healthy individual while person Y can be hypoglycemic.
(iii) Lowering of blood glucose level in X is brought about by utilisation of glucose in respiration and excretion through urine.
A. (ii) and (iii) only
B. (i) only
C. (i) and (iii) only
D. (i) and (ii) only
Answer : A