CBSE Class 6 Science NSO Olympiad MCQs with Answers Set O

SCIENCE

Question. The given figure shows a zinc bar placed near a strong magnet. Four compasses P, Q, R and S are arranged near by the magnet and the zinc bar as shown. Which one of the compasses does point to the wrong direction?

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

Question. Which of the following statements are true?
(i) A shadow is formed on the same side of the object as the source of light.
(ii) The image formed by a pinhole camera is always erect.
(iii) We see stars because they reflect light from the sun.
(iv) The shadow of a pole is longest in the evening and shortest at the noon.
(v) Mirrors are good reflectors of light.
A. (i), (ii) and (iii) only
B. (i), (ii) and (iv) only
C. (iv) and (v) only
D. (i), (ii), (iii) and (v) only
Answer : C

Question. The given circuit shows an electric cell connected to a bulb through conducting wires. Identify the direction of current flow in the circuit.

A. PQRS
B. SRQP
C. PQSR
D. QPRS
Answer : B

Question. A pendulum takes 0.8 seconds to swing from the extreme points A to B. What will be the time taken for the pendulum to make 15 oscillations ?

A. 12 seconds
B. 24 seconds
C. 36 seconds
D. 48 seconds
Answer : B

Question. A card with the word MEASUREMENT written on it, is placed in front of a plane mirror as shown in the figure. The image of the word MEASUREMENT seen in the mirror is

Answer : B

Question. Read the given statements and select the correct option.
Statement 1 : The displacement of a body may be zero, though distance can be finite.
Statement 2 : If a body moves such that finally it arrives at initial point, then displacement is zero while distance is finite.
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. Statement 1 is false and statement 2 is true.
Answer : A

Question. A light steel bar and a light iron bar are attracted to a magnet for a long time as shown in the figure. What will possibly happen when the magnet is removed?

A. The steel and iron bars repel each other.
B. Both steel and iron bars lose their magnetism.
C. Steel bar retains its magnetism and iron bar loses its magnetism.
D. Iron bar retains its magnetism and steel bar loses its magnetism.
Answer : C

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

A. (i)-(a, b), (ii)-(e), (iii)-(d), (iv)-(c), (v)-(a)
B. (i)-(e), (ii)-(c), (iii)-(a, e) (iv)- (c), (v)-(e, d)
C. (i)-(c, d), (ii)-(d), (iii)-(a, b), (iv)- (e), (v)-(a)
D. (i)-(e), (ii)-(c), (iii)-(a, b, c), (iv)-(e), (v)-(d)
Answer : D

Question. A bar magnet is dipped in iron filings and taken out.
Which of the following observations is correct?
A. The maximum quantity of filings gets sticked to the ends of the magnet.
B. The maximum quantity of filings gets sticked to the middle.
C. The filings gets uniformly distributed.
D. The maximum quantity will be sticked at the north pole only.
Answer : A

Question. In the given circuit diagram, S1, S2 and S3 are switches.
Which of the following switch combinations is correct for the lamp to glow?

          S1                 S2                  S3
A. Opened          Opened         Closed
B. Closed           Closed           Opened
C. Opened         Closed           Opened
D. Closed           Opened         Closed
Answer : D

Question. The given diagram shows four gears. Dev applied a force to make the largest gear L, rotates in a clockwise direction as shown. In which direction will gears X, Y and Z rotate?

               X                          Y                         Z
A. Anti-clockwise       Anti-clockwise        Clockwise
B. Anti-clockwise       Clockwise              Anti-clockwise
C. Clockwise Anti-     clockwise               Clockwise
D. Clockwise Anti-     clockwise               Anti-clockwise
Answer : B

Question. Two identical metal balls A and B moving in opposite directions with different speeds hit each other at point O as shown in the figure. Changes are most likely to appear in their

A. Shapes and speeds
B. Speeds and directions
C. Directions and volumes
D. Volumes and shapes.
Answer : B

Question. In ancient times, people used different units of measurement of length and distance.
Some of them are P. Cubit Q. Footstep R. Handspan S. Arm length
The correct arrangement in terms of their increasing length is
A. R, Q, P, S
B. R, P, Q, S
C. R, P, S, Q
D. R, S, P, Q
Answer : A

Question. During the science activity, Ms. Rakhee conducted the following experiments :
Experiment I : 10 g of rock crystals of common salt were dissolved in 50 mL of water at 30°C.
Experiment II : 30 g of finely powdered common salt was dissolved in 50 mL of water at 60°C.
Experiment III : 10 g of rock crystals of common salt were dissolved in 100 mL of water at 30°C.
Experiment IV : 10 g of finely powdered common salt was dissolved in 100 mL of water at 60°C.
In which experiment common salt took the shortest time to dissolve ?
A. Experiment I
B. Experiment II
C. Experiment III
D. Experiment IV
Answer : D

Question. Identify W, X, Y and Z.
W : An edible liquid miscible in water
X : A non-edible, inflammable liquid that floats on water
Y : An edible, coloured liquid that does not flow easily
Z : A colourless, non-inflammable liquid

Answer : B

Question. Shubhi classified some changes around us as shown in the table

Which of these changes are correctly classified?
A. 1 and 3 only
B. 3 and 5 only
C. 4 and 5 only
D. None of these
Answer : B

Question. Study the given Venn diagram carefully and identify (i), (ii), (iii) and (iv).

Answer : C

Question. The given flowchart was prepared by Neelima for sorting materials into different groups. She handed over the chart to her teacher with few blanks. Fill in the blanks by choosing an appropriate option

Answer : B

Question. Which of the following statements is/are incorrect?
I. Decantation can separate a liquid from an insoluble solid after sedimentation.
II. A mixture of milk and water can be separated by using separating funnel.
III. In hot water there is no limit to the amount of sugar that will dissolve in it.
IV. When detergent is added to oil-water mixture, it can be separated easily.
A. I only
B. II and IV only
C. I and III only
D. II, III and IV only
Answer : D

Question. Ria was observing her mother cooking dinner in the kitchen. She tried to identify materials being used and their nature.

The given table represents her observations.

Which of her conclusions are incorrect?
A. I, III and IV only
B. II and IV only
C. I and IV only
D. None of these
Answer : C

Question. Ms. Shobhna conducted a science activity in following steps :
I : She made crystals of pure copper sulphate from an impure sample.
II : She dissolved the crystals in pure water to make a blue solution.
III : She added a metallic piece into the copper sulphate solution and after some time colour of the solution changed to green.
Which of the following statements is correct regarding this activity?
A. Step I involves a physical change while steps II and III involve chemical changes.
B. Steps I and II involve physical changes while step III involves chemical change.
C. All the steps involve physical changes.
D. All the steps involve chemical changes.
Answer : B

Question. Change X : Cooling a mixture of air and kerosene vapours so that liquid kerosene condenses out.
Change Y : Burning a mixture of air and kerosene vapours.
What type of changes X and Y are?
A. X – Chemical change, Y – Reversible change
B. X – Physical change, Y – Chemical change
C. X – Chemical change, Y – Physical change
D. X – Reversible change, Y – Physical change
Answer : B

Question. Match column I showing the properties of components of a mixture with column II showing methods of separation and select the correct answer from the given codes.

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

Question. Shobhit a class 6 student, took some samples and struck each with a hammer. He noted down his observations in the given table.

Identify (i), (ii) and (iii).
       (i)                 (ii)              (iii)
A. Brittle        Malleable        Soft
B. Soft           Ductile            Brittle
C. Soft           Malleable       Brittle
D. Brittle        Ductile            Soft
Answer : C

Question. To separate constituents of a mixture, Varsha adopted the following methods :

What could be the methods (X) and (Y)?
A. (X) → Loading ; (Y) → Condensation
B. (X) → Filtration ; (Y) → Evaporation
C. (X) → Sedimentation ; (Y) → Decantation
D. (X) → Distillation ; (Y) → Centrifugation
Answer : B

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

A. P is formed when our body is exposed to sunlight.
B. Deficiency of P or Q can cause rickets.
C. Q is present in milk and its products.
D. P is vitamin D whereas Q could be calcium or sodium.
Answer : D

Question. Refer to the given pie chart showing nutrients P, Q, R and S present in different foods and identify the correct statements regarding them.

(i) Food rich in P is taken by sportspersons which provides them with instant energy and it turns blue-black in colour on adding iodine solution.
(ii) S helps in retaining water in the body and maintains healthy bowel movement.
(iii) S is important for growth and repair of body tissues thus, required in more amount in person recovering from accident injuries.
(iv) R forms antibodies in the body and its deficiency causes marasmus characterised by dry and rough hair, swollen stomach and mental retardation in children.
(v) Food sample containing Q turns into purple or violet colour when treated with 2 drops of copper sulphate and sodium hydroxide solution.
A. (i), (iii) and (iv) only
B. (ii), (iii), (iv) and (v) only
C. (i), (ii) and (v) only
D. (ii), (iii) and (iv) only
Answer : C

Question. Match column I with column II and select the correct option from the given codes.
    Column I                             Column II
1. Weft             p. Tying knots in yarn to make carpets, etc.
2. Felt              q. Longitudinal threads running across the fabric
3. Knotting        r. Filling threads running horizontally across the length of fabric
4. Warp            s. Fabric made by pressing fibres together
A. 1 → r, 2 → s, 3 → p, 4 → q
B. 1 → q, 2 → r, 3 → s, 4 → p
C. 1 → p, 2 → q, 3 → r, 4 → s
D. 1 → s, 2 → q, 3 → p, 4 → r
Answer : A

Question. Which of the following joints shows the given characteristics?
(i) It allows movement in one plane only.
(ii) It allows back and forth or up and down movement.

Answer : A

Question. Read the given statements and select the option stating which ones are true (T) and which ones are false (F).
(i) In cactus, leaves are reduced to spines and stems perform photosynthesis.
(ii) Mountain goats have cloven hooves for climbing rocky slopes of mountains.
(iii) In lion, eyes are placed in front of his head to look in all directions.
(iv) Deer have long ears to hear sound of slight movements of their predators.
(v) Frogs have strong foreleg muscles which help them leap around to catch their prey.
(vi) Submerged plants have thin, ribbon like leaves to withstand water currents of flowing water.
    (i)     (ii)      (iii)    (iv)      (v)       (vi)
A. F       T         T       F         T         F
B. T       T         F       F         T         F
C. T       F         T       T         F         T
D. T       T         F       T         F         T
Answer : D

Question. Ridhan classified animals in four groups on the basis of their feeding habits. In doing so, he wrongly placed one animal in one of the groups. Identify this group and select the correct option. 
A. Giraffe, rabbit, wildebeest and deer
B. Crocodile, crow, snake and eagle
C. Leech, mosquito, lice and bed bug
D. Tiger, snow leopard, wolf and lion
Answer : B

Question. Read the given passage and select the option which correctly fills any three of the blanks.
 (i) is the main source of water on Earth however (ii) , is considered more pure than (i) as it is free from contaminants. City roads flooded with water, dry up due to the process of (iii) . Rate of (iii) increases with (iv) in temperature. The process of (v) changes water vapour present in air into water. (iii) and (v) help in circulating water between hydrosphere and atmosphere.
A. (i)-Groundwater, (ii)-Rainwater, (iv)-Decrease
B. (ii)-Underground water, (iii)-Evaporation, (v)-Transpiration
C. (i)-Surfacewater, (ii)-Groundwater, (iv)-Decrease
D. (ii)-Groundwater, (iv)-Increase, (v)-Condensation
Answer : D

Question. Which among the following statements is incorrect?
A. Cigarette paper is commonly made from flax fibre.
B. Silk is obtained from larva of silkworm, fed on leaves of mulberry trees.
C. Cotton grows well in black soil rich in humus.
D. Coir is obtained from husk, which is separated from coconut by soaking them in water.
Answer : B

Question. Read the given statements and select the correct option.
Statement 1 : Animals cannot take nitrogen directly from atmosphere rather they obtain it from plants they eat.
Statement 2 : Plants also cannot take nitrogen directly from atmosphere, rather free living or symbiotic nitrogen fixing bacteria present in soil convert atmospheric nitrogen into soluble nitrogen compounds that can be used by plants.
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. Read the following passage carefully.
P is found abundantly in cod liver oil and is important for visual efficiency. Q is sourced from amla, tomato and citrus fruits and its deficiency may cause wounds
to take longer time for healing. R is formed in our body in presence of sunlight and its deficiency in toddlersmay cause deformity of legs.
Now select the incorrect option regarding this.
A. P can be found in spinach but not R.
B. In absence of R our body will show calcium deficiency even if it is abundant in our food.
C. Q is also called B-complex as many of its varieties are available.
D. P cannot be dissolved in water.
Answer : C

Question. Refer to the given flow chart and identify (i) – (iv)

          (i)                       (ii)                  (iii)                (iv)
A. Cockroach         Snake              Penguin         Frog
B. Earthworm        Scoliodon         Dolphin          Sparrow
C. Leech                Crocodile         Starfish          Whale
D. Snail                 Silverfish          Shark             Ostrich
Answer : B

Question. Class teacher gave four different samples of fibres to four students. Ria has fibre H, which is obtained from plant that grows best in alluvial soil in warm and humid climates. Fibre I given to Sumit gives smell of burning hair on being burnt and has ability to trap air and heat, while fibre J given to Kanika, is a fibre obtained from an insect. Fibre K given to Rahul burns with smell of burning plastic. Identify the fibres H, I, J and K and select the correct option regarding them.
A. Fibre H is the cheapest vegetable fibre and is also known as golden fibre.
B. Fibre I is obtained from passion vine and can be worn both in summers and winters.
C. Fibre J does not absorb water at all hence is used in making raincoats.
D. Fabric made of fibre K can absorb sweat, thus is comfortable to wear in hot and humid weather.
Answer : A

Question. Which statement is incorrect regarding the given figure?

A. Process Q helps to obtain salt from sea water.
B. The mirror in the bathroom becomes foggy when we take hot shower due to process P.
C. Process S results in dew drops on surface of leaves in winter morning.
D. Process R is decelerated if humidity in the air is high.
Answer : C

Question. Given images show various steps in processing of cotton fibre into fabric. Arrange these steps in correct sequence.

A. (iv) → (iii) → (ii) → (i) → (v)
B. (iv) → (ii) → (v) → (iii) → (i)
C. (iv) → (ii) → (iii) → (v) → (i)
D. (iv) → (i) → (ii) → (v) → (iii)
Answer : D

Question. To increase the crop yield, farmers in an area started using chemical fertilisers and pesticides tremendously which caused runoff pollution of a river flowing nearby.
Which of the following graphs correctly shows the changes in levels of dissolved oxygen and bacteria present in this river? 

Answer : A

Question. Read the features of a plant as given below.
(i) Roots are much reduced in size.
(ii) Stems are generally long and narrow.
(iii) Stems possess air spaces.
(iv) Leaves are large and flat.
(v) They have waxy upper surfaces.
To which of these habitats does this plant belong?
A. Desert
B. Tropical rainforest
C. Aquatic
D. Polar region
Answer : C

Question. The given figure shows an experiment performed to study the nature of the given cloth. When the strip of cloth was burning it smelled like a burning grass, and is not self extinguishing. What is likely to be the nature of the cloth ?

A. Wool
B. Jute
C. Cotton
D. Silk
Answer : B

Question. A camel is shown here with some of its body parts labelled 1-4. Some adaptations of camel are given in the following list. Select the correct match of the adaptation and the body part.

a. Stored fat can be respired to release water
b. Help to eat thorny plants without injury
c. Large area makes movement more efficient
d. Can be closed to prevent entry of sand
A. a-2, b-3, c-4, d-1
B. a-4, b-2, c-3, d-1
C. a-1, b-2, c-3, d-4
D. a-3, b-4, c-1, d-2
Answer : B

Question. A rubbish bin containing discarded food was carelessly left uncovered for five days. Various components during these days changed, which are plotted in the given graph.

Select the correct option regarding the components (W-Y).
A. X can be non-biodegradable material.
B. W can be the number of flies found at the rubbish bin.
C. Y can be the amount of biodegradable material present in the rubbish bin.
D. All of these
Answer : D

Question. The table shows the composition and energy content of four common foods.

Select the correct option regarding it.
A. Shweta is affected with rickets, she should be preferably given food P.
B. Ms. Sharma is having an artery disease, she should prefer food P.
C. Rahul who is a body builder should prefer food Q.
D. Kanishka is having bleeding gums and joint pain, she should be preferably given food R and S.
Answer : A

ACHIEVERS SECTION

Question. The given figure shows the inside view of a torch. 
Identify the wrong statements regarding the marked parts and its respective descriptions.
(i) Part that either breaks the circuit or completes it - 1
(ii) Part which converts chemical energy into electric energy - 2
(iii) Part that reflects light - 3
(iv) Negative terminal of electric cell - 4
(v) Positive terminal of electric cell - 5

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

Question. The given figure shows different arrangements of particles of an unknown substance undergoing changes I, II, III and IV.

Fill in the blanks by choosing an appropriate option.
The change(s) (p) involve(s) absorption of heat while change(s) (q) involve(s) evolution of heat.
In all these changes, (r) of the substance remains constant.
      (p)              (q)                   (r)
A. I, II             III, IV             Volume
B. III               I, II, IV           Mass
C. I, II, IV       III                   Mass
D. I, II, IV       III                   Energy
Answer : C

Question. Read the given passage.
P is a modified underground stem and is an energy giving food. Q is a root that stores food and gets swollen. Nutrient present in Q keeps eyes and skin healthy. R and S are edible seeds. Nutrient in R gets stored in the body and keeps the body warm, while nutrient in S helps in growth and repair of body. T is edible leaf, the nutrient of which helps in formation of blood and its deficiency affects blood clotting. Which of the following statements hold true regarding it?
(i) P could be potato and the deficiency of main nutrient present in it causes kwashiorkor.
(ii) Q could be carrot which contains vitamin A.
(iii) R could be groundnut that majorly yields oil.
(iv) S could be rajma or gram which is rich in fat.
(v) T could be spinach with main nutrients iron and vitamin K.
A. (i) and (ii) only
B. (iii) and (iv) only
C. (ii), (iii) and (v) only
D. (i), (iii) and (v) only
Answer : C

Question. Refer to the given food web.

Answer : C

Question. Study the given flow chart and select the correct option

Answer : D