CBSE Class 7 Science NSO Olympiad MCQs with Answers Set G

LOGICAL REASONING

Question. In a certain code language, 'CIRCULAR' is written as 'TCNWETKE'. How will 'COMPUTER' be written in the same language?
A. THVVWRQF
B. TGVWRPRF
C. TGVVQOQE
D. TGVWROQE
Answer : D

Question. There is a certain relationship between figures (1) and (2). Establish a similar relationship between figures (3) and (4) by selecting a suitable figure from the options which will replace the (?) in figure (4).

Answer : B

Question. In a row of students, Rahul is 12th from the left end and Shikha is 17^th from the right end. If they interchange their positions, Shikha becomes 27th from the right end. How many total students are there in the row?
A. 38
B. 36
C. 39
D. 41
Answer : A

Question. The sheet of paper shown in Fig. (X) is folded to form a cube. Select the figure from the options that is similar to the cube formed by folding the given sheet.

Answer : D

Question. If the digits '6' and '4', signs '+' and '×' are interchanged on the left hand side of each option, then which of the following options becomes correct?
A. 6 + 4 × 2 = 26
B. 4 + 6 × 2 = 12
C. 6 × 4 + 2 = 20
D. 4 × 2 + 6 = 8
Answer : A

Question. How many such pairs of letters are there in the word PURPOSEFUL each of which has as many letters between them in the word as there are in the English alphabet?
A. One
B. Two
C. Three
D. More than three
Answer : D

Question. Find the missing figure in the given figure matrix.

Answer : A

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

Answer : B

Question. Study the given Venn diagram carefully and answer the following question.

How many doctors are players but not actors?
A. 3
B. 4
C. 8
D. 17
Answer : B

Question. Which of the following options satisfies the same conditions of placement of dots as in Fig. (X)?

Answer : D

SCIENCE

Question. The distance-time graph of a motorcycle is shown in the figure. When was the motorcycle travelling at a speed of 2 m s^–1?

A. 2.5 s
B. 5.0 s
C. 8.0 s
D. 10.5 s
Answer : D

Question. The melting and boiling points of four different substances are shown in the table. The room temperature is 30°C.

Which of the following statements are incorrect about the data given in the table?
(i) Substance P is in solid state at room temperature.
(ii) Substance Q is in liquid state at room temperature.
(iii) Substance R is gas at –150°C and solid at –220°C.
(iv) Substance S is in solid state at room temperature.
A. (i) and (ii) only
B. (i), (ii) and (iii) only
C. (iii) and (iv) only
D. (i), (ii), (iii) and (iv)
Answer : B

Question. Match column I with column II and select the correct option.
    Column I                              Column II
P. Plane mirror             (i) Used as a magnifying glass
Q. Concave mirror       (ii) Can form image of objects spread over a large area
R. Convex mirror         (iii) Used by dentists to see enlarged image of teeth
S. Concave lens          (iv) The image formed is erect and of the same size as the object
T. Convex lens             (v) Is known as diverging lens
A. P-(iv), Q-(ii), R-(i), S-(iii), T-(v)
B. P-(ii), Q-(iii), R-(i), S-(v), T-(iv)
C. P-(iii), Q-(ii), R-(iv), S-(v), T-(i)
D. P-(iv), Q-(iii), R-(ii), S-(v), T-(i)
Answer : D

Question. Read the given statements and select the correct option.
Statement 1 : The cyclone consists of a high pressure region with low pressure all around.
Statement 2 : The winds tend to blow towards the low pressure region and circulate violently around the centre of cyclone with great speed.
A. Both the statements 1 and 2 are true and statement 2 is the correct explanation of statement 1.
B. Both the 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 : D

Question. In which diagram(s) is/are the correct poles of the electromagnet indicated?
(N indicates North pole and S indicates south pole.)

A. 2 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2 and 3
Answer : A

Question. A particle moves on a circular path of radius R as shown in figure.

The distance travelled and displacement of the particle from point A to point C respectively are
A. πR/2, 2R
B. pR, 2R
C. πR/2, πR/2
D. πR, πR
Answer : B

Question. A circuit diagram is shown here. Which of the switches must be closed so that only bulb 2 lights up ?

A. P, R and T only
B. R and T only
C. R, S and T only
D. P, Q, R, S and T
Answer : A

Question. When a light ray is reflected repeatedly by a set of parallel plane mirrors, the intensity of the light ray decreases after some reflections. This is because of
A. Poor reflection from mirrors
B. Absorption of some amount of light by mirrors
C. Scattering of light by mirrors
D. None of these.
Answer : B

Question. On holding a stainless steel spoon near our face, we see
A. Our inverted image on outer side of the spoon
B. Our erect image on inner side of the spoon
C. Our inverted image on inner side of the spoon
D. Both B and C are possible.
Answer : D

Question. Four light bulbs are concealed from an observer by an opaque wall as shown. Without shifting the positions of the observer and the bulbs, how many bulbs can the observer see from the mirror?

A. 1
B. 2
C. 3
D. 4
Answer : C

Question. Which of the following statements is/are correct?
I. Acids are sour in taste and corrosive in nature.
II. Fruits and vegetables contain inorganic acids.
III. All bases are soluble in water.
IV. Bases produce salts with all metals.
V. Milk of magnesia is an aqueous solution of magnesium carbonate.
A. II and IV only
B. I only
C. III and V only
D. I, II, III, IV and V
Answer : B

Question. Study the given flow chart carefully.

Changes i, ii, iii and iv could be respectively
A. Fast, non-periodic, reversible and chemical
B. Undesirable, periodic, reversible and fast
C. Fast, chemical, irreversible and non-periodic
D. Undesirable, reversible, chemical and irreversible.
Answer : B

Question. A few changes are listed in the box :
(i) Cutting of hair
(ii) Mixing fruits and cornflakes
(iii) Adding baking soda to vinegar
(iv) Spoiling of food
(v) Bending of a piece of metal on heating 
(vi) Decomposition of old leaves
(vii) Shredding of paper
Which of the following represents their correct classification?

Answer : A

Question. Identify W, X, Y and Z in the given flow chart.

Answer : C

Question. Observe the given figure carefully and select the correct statements.

I. Heat is evolved in this reaction.
II. The colour of the mixture in the conical flask is pink in the beginning.
III. It represents a neutralisation reaction.
IV. No new substance is formed in the reaction.
A. I, II and III only
B. II and III only
C. III and IV only
D. I, II, III and IV
Answer : A

Question. Somya took water in five different tumblers (I-V) and added different substances to each tumbler. She stirred the contents with spoon and then recorded her observations in the given table.

The correct observations and inferences are
A. I, II and IV only
B. III and V only
C. IV and V only
D. None of these
Answer : B

Question. Study the given figure carefully.

Which of the following reactions explains the above change most appropriately?
A. ZnSO₄ + Cu → CuSO₄ + Zn
B. CuSO₄ + Fe → FeSO₄ + Cu
C. FeSO₄ + Cu → CuSO₄ + Fe
D. CuSO₄ + Zn → ZnSO₄ + Cu
Answer : B

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

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

Question. Refer to the given flow chart and select the option that correctly identifies organisms P, Q, R and S.

Answer : C

Question. Aryan took two food samples X and Y in separate test tubes. He added 2-3 drops of Benedict’s solution in food sample X and heated it while he added two drops of copper sulphate solution and few drops of caustic soda solution in food sample Y. He observed that sample X turned orange while sample Y turned violet.
Which of the following is correct regarding X and Y?
A. X could be egg while Y could be boiled potato.
B. X could be ripened banana while Y could be milk.
C. X could be wheat while Y could be butter.
D. X could be milk while Y could be rice.
Answer : B

Question. Select the incorrect match.
(i) Ammonotelism  -   Sponges, Hydra, Cartilaginous fish, Leech, Crocodile
(ii) Ureotelism        -   Frog, Toad, Bony fish, Turtle, Man, Land Snail
(iii) Uricotelism      -   Cockroach, Pigeon, Tortoise, Lizard, Snake
A. (i) and (ii) only
B. (ii) and (iii) only
C. (iii) only
D. (i), (ii) and (iii)
Answer : A

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

A. P is a cellulosic fibre whereas Q and R are protein fibres.
B. P could be sisal, Q could be wool and R could be cotton.
C. Q could be obtained from the same animal repeatedly whereas R could be obtained from an animal only once in its lifetime.
D. Processing of fibres P, Q and R may involve retting, shearing and reeling steps, respectively.
Answer : B

Question. Read the given paragraph.
Pollination processes P, Q or R are requisite for accomplishment of sexual reproduction in plants. P does not require any external agent but Q and R do.
P and Q help in producing purelines whereas R gives rise to offspring showing variations among themselves.
Identify processes P, Q and R and select the correct option regarding these.
A. Process P is possible in both unisexual and bisexual flowers.
B. Sexual reproduction in papaya and cucurbit is accomplished through processes P and Q both.
C. In case of Maple and Dandelion, wind serves as an agent for completion of process R.
D. Sunflower and Rafflesia produce bright showy flowers with nectar and odour to attract bats for completion of process Q.
Answer : C

Question. Refer to the given flow chart and select the incorrect option regarding organisms P, Q, R, S and T.

A. P may have a pair of tentacles which bear simple eyes at the tip whereas body of Q may be metamerically segmented.
B. S could be a warm blooded stork whereas T could be a cold blooded arowana.
C. R may bear jointed appendages and undergoes moulting during its growth phase.
D. T may respire through gills whereas S possesses lungs as its respiratory organs.
Answer : C

Question. Refer to the given food chain operating in an ecosystem.
                         Producer → P →  Q → R
A population of organism X is introduced in this community which exclusively feeds on Q. Which of the following graphs correctly shows the changes in populations of P and R over time?

Answer : B

Question. The given graph shows the effect of pH on the activity of four different enzymes (P, Q, R and S). Which of the following correctly identifies enzyme found in the stomach, small intestine and one not affected by pH?

Answer : D

Question. Manya wanted to find out if plants absorb water through their roots, so she decided to conduct an experiment.
Which of the following two set-ups should she choose to conduct a fair test?

A. P and Q
B. Q and S
C. Q and R
D. None of these
Answer : A

Question. To prepare a blood smear slide a student placed a drop of blood on a glass slide and added a drop of distilled water to dilute the blood. He then added stain (a coloured chemical used to see the cells) to it before placing the coverslip over it. When viewed, under the microscope he could not see the blood cells.
Which of the following best explains this?
A. The blood cells had burst.
B. The blood had dried before the water was added.
C. The drop of water diluted the blood too much and cells dispersed too far away from each other.
D. The water caused the cells to shrink.
Answer : A

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

A. P has thick layer of subcutaneous fat for effective insulation against cold.
B. P is cold blooded whereas Q is warm blooded.
C. P is penguin which is adapted to live in extremely cold regions whereas Q could be Siberian crane which escapes harsh winters by migrating to warmer lands.
D. Both P and Q may have webbed feet but P is adapted to swimming whereas Q may swim and fly both.
Answer : B

Question. If a person is unable to breathe on his own due to some medical illness, an iron lung may be employed to take over the role of the diaphragm and the intercostal muscles. The person is placed in a cylindrical chamber called iron lung while his head remains outside the cylinder. An airtight seal is placed around his neck.
Changes in the air pressure within the iron lung allow the flow of air into and out of his lungs.
Which of the following statements about the iron lung is correct?
A. Breathing with an iron lung is still possible if the patient's trachea is completely blocked.
B. During exhalation, the iron lung causes the patient's lungs to expand.
C. During inhalation, the pressure in the patient's lungs is increased.
D. Inhalation and exhalation is possible even if the patient's lung is punctured.
Answer : D

Question. Which of the following is the most effective way to measure the effect of different carbon dioxide concentrations on the rate of photosynthesis?
A. Placing same amount of dry ice in similar bell jars kept in sunlight containing different plants.
B. Using different concentrations of sodium hydrogen carbonate solution with same type of immersed water plants in similar bell jars placed in sunlight.
C. Varying light intensity given to different well watered plants placed in similar bell jars kept in sunlight.
D. Varying amount of air provided to different well watered plants placed in similar bell jars kept in sunlight.
Answer : B

Question. Saurashtra, a land with history of severe water scarcity, hostile climate and rocky land is now self sufficient in water availability due to the efforts of _____ who taught the local people the importance of rainwater harvesting.
A. Rajendra Singh
B. Shamjibhai J. Antala
C. Amla Ruia
D. Aabid Surti
Answer : B

Question. Refer to the given dichotomous key.
I. (a) Food is obtained from plants. - Go to II
(b) Food is obtained from animals. - Go to III
II. (a) Food is obtained from roots of plants. – P
(b) Food is obtained from seeds of plants. – Q
III. (a) Food is categorised as energy giving food. – R
(b) Food is categorised as body building food. – S
Now select the correct option regarding food P, Q, R and S.
A. P could be fenugreek whereas Q could be corn or maize.
B. R could be egg whereas S could be honey.
C. R could be obtained from a flying insect whereas S could be obtained from both oviparous and viviparous animals.
D. P could be turmeric or ginger whereas Q could be rice or lentils.
Answer : C

Question. Rahul took equal amount of three types of soil X, Y and Z in different vessels, each with pores at the bottom. He then poured equal amount of water over each sample one by one and tabulated the percolation rate of these three samples as represented by the given graph.

Select the correct option regarding this.
A. Soil Y shows highest water retention and is best suited for making the bottom of an artificial pond.
B. Soil Y is present in marshes whereas soil Z is abundantly found at sea shores.
C. Soil Y is well drained whereas soil X is not, hence is often water logged.
D. Soil X is well aerated hence ideal for growth of plant roots whereas plants growing in soil Z possess aerial roots or pneumatophores as it is water logged.
Answer : C

Question. Study the given relationship.
Fruit peel :: Used syringe :: Plastic tiffin
Select the option that satisfies the same relationship.
A. Chapati :: Used urine bag :: Glass bottles
B. Newspaper :: Blood sample :: Cooked beans
C. Spectacles :: Rotten vegetable :: Mirror
D. Metal keys :: Newspaper :: Animal excreta
Answer : A

ACHIEVERS SECTION

Question. Refer to the given graph and identify habitats P, Q, R and S.

Now, select the option that correctly matches the habitat with the type of adaptation shown by organisms inhabiting them.

Answer : B

Question. In the arrangements I and II shown in figure, four pins W, X, Y and Z are fixed to a metal loop and metal rod with the help of wax. Loop and rod are made of same material and equal thickness. Which set of pins will fall simultaneously? (r is the radius of the loop.)

A. Y and Z only
B. W, X and Y only
C. W and X only
D. W, X, Y and Z
Answer : C

Question. A few solutions were tested with different indicators and results were noted down in the given table.

Study the given table carefully and fill in the blanks by choosing an appropriate option.
Solution(s) (i) will have no effect on blue litmus paper while solution(s) (ii) will turn blue litmus red. Phenolphthalein remains colourless in solution(s) (iii) while it changes to pink colour in solution(s) (iv) 

Answer : B

Direction (Q. No. a and b): Read the given passage having some variables and few italicised words.
Different respiratory organs are present in different organisms. X is the main respiratory organ in humans. Respiratory system of cockroach consists of small openings on the sides of its body called tracheoles which are connected to the tubes called tracheae that are further branched into spiracles. Scoliodon respires through Y which is richly supplied with blood vessels. Z is the main site of gaseous
exchange in plants. Each Z is guarded by two kidney shaped subsidiary cells which are further flanked by specialised epidermal cells called guard cells.

Question a. Identify X, Y and Z in the given passage and select the incorrect option regarding them.
A. Whales and dolphins also have X as their respiratory organ where alveoli is the main site of gaseous exchange.
B. Y is the respiratory organ in tadpole larva and sea horse.
C. Z is absent in all hydrophytes but is abundantly present on the upper leaf surface of all xerophytes.
D. When pressure inside X drops, inspiration occurs and when pressure inside X starts increasing the air contained in it is pushed out causing expiration.
Answer : C

Question b. Select the correct option regarding the words italicised in the given passage.
A. The positions of spiracles and tracheoles should be interchanged.
B. The position of tracheoles and tracheae should be interchanged.
C. Subsidiary should not be replaced as it is correctly mentioned.
D. Guard should be replaced by lenticel.
Answer : A