CBSE Class 7 Science NSO Olympiad MCQs with Answers Set E

LOGICAL REASONING

Question. Which of the following figures do not satisfy the same condition of placement of dots as in Fig. (X)?

Answer : A

Question. Which of the following is the net of the given Fig. (X)?

Answer : A

Question. Find the missing number, if same rule is followed in all the three figures.

A. 16
B. 18
C. 10
D. 14
Answer : B

Question. Read the following information carefully.
'A@B' means 'A is added to B'.
'A*B' means 'A is multiplied by B'.
'A#B' means 'A is divided by B'.
'A$B' means 'B is subtracted from A'.
Total age of 12 boys is 'X' and the total age of 13 girls is 'Y'. What is the average age (A) of all the boys and girls together ?
A. A = (X@Y) # 25
B. A = (X$Y) # 25
C. A = (X@Y) * 25
D. None of these
Answer : A

Question. There are 8 friends A, B, C, D, E, F, G and H seated in a circle facing the centre. AC, DG, HE and FB are seated adjacent to each other. A is also seated adjacent to H. B is second to the right of H. E is third to the right of C.
What is C's position with reference to F?
A. 5th to the right
B. 4th to the left
C. 4th to the right
D. 3rd to the right
Answer : D

Question. There is a certain relationship between figures (1) and (2). Establish the same relationship between figures (3) and (4) by selecting a suitable figure from the options that would replace the (?) in Fig. (4).

Answer : D

Question. If the first and the second digits of each of the following numbers are interchanged, then which number will be the smallest?
358 426 853 674 592
A. 358
B. 426
C. 853
D. 674
Answer : B

Question. Two positions of a dice are shown below. If the face with 1 dot is at the bottom, then the number of dots on the top face is

A. 2
B. 3
C. 4
D. 5
Answer : B

Question. In a certain code language, the word FIENDISH is written as DFHNSEII. How will the word HESITATE be written in that language?
A. HSTTEEAI
B. HTTSAEEI
C. HSTTAEEI
D. HSTTIEEA
Answer : C

Question. Select a figure from the options, which when placed in the blank space of Fig. (X) would complete the pattern.

Answer : A

SCIENCE

Question. Sagar wants to magnetise an iron bar EF by the stroking method. The given figure shows the direction of stroke.

Which of the following is a possible set of polarities for the given arrangement?
        P           Q           E            F
A. North    South    South     South
B. North    South    North     North
C. South    North    South     North
D. South    North    North     South
Answer : C

Question. A photographer wishes to take pictures without being noticed. He sets up two plane mirrors together with his camera. Which arrangement of mirrors will allow the photographer to take pictures of someone behind the camera?

Answer : C

Question. The diagram shows a man standing under a shelter on a sunny day. Given that the man feels hot, which of the following shows the processes of how thermal energy from the Sun reaches the man?

A. Radiation → Conduction → Radiation
B. Radiation → Conduction → Convection
C. Radiation → Convection → Radiation
D. Radiation → Convection → Convection
Answer : A

Question. Read the given statements and select the correct option.
Statement 1 : It is difficult to ride a bicycle against the direction of wind.
Statement 2 : High speed winds are accompanied by increased air 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. Both statements 1 and 2 are false.
Answer : C

Question. Match Column-I with Column-II and select the correct option.
     Column-I                            Column-II
(a) Railway engine                (i) Quintal
(b) Packet of chilli powder     (ii) kg
(c) Sack of wheat                  (iii) mg
(d) Huge bag of sand            (iv) g
(e) Aspirin tablet                    (v) Metric ton
A. (a) - (v), (b) - (iv), (c) - (i), (d) - (ii), (e) - (iii)
B. (a) - (i), (b) - (ii), (c) - (iii), (d) - (iv), (e) - (v)
C. (a) - (ii), (b) - (iv), (c) - (v), (d) - (iii), (e) - (i)
D. (a) - (iii), (b) - (ii), (c) - (iv), (d) - (v), (e) - (i)
Answer : A

Question. Two parallel rays of light strike a concave lens. Which of the following correctly shows the passage of the rays after passing through the lens?

Answer : B

Question. Misha, a class VII student suggests the given circuit setup.
Her teacher said that this circuit is unsafe because

A. The switch is wrongly connected
B. The fuse is wrongly connected
C. The bulb is fused
D. Live wire and neutral wire have been interchanged.
Answer : B

Question. Three liquids with their respective boiling and freezing points are shown in the given table.

A thermometer that can measure both –50°C and 38°C should be filled with __________.
A. Mercury only
B. Alcohol only
C. Pentane only
D. Either alcohol or pentane
Answer : B

Question. Solve the following riddle by identifying X, Y, Z.
X : I am present in a closed circuit only.
Y : I am a source of energy available in different shapes and sizes.
Z : I am a device used for making and breaking the electric circuit.
              X                               Y                             Z
A. Electric current        Electric switch           Electric cell
B. Electric switch         Electric cell                Electric current
C. Electric current        Electric cell                Electric switch
D. Electric cell             Electric current           Electric switch
Answer : C

Question. Two identical balls are released at the same time from a building of height 85 m, one from the top while the other from half way up.
Which of the following quantities is same for both balls?
A. Time of travel
B. Final speed
C. Acceleration
D. Total displacement
Answer : C

Question. Which of the following statements is/are correct?
I. Coffee is bitter in taste hence, it is basic in nature.
II. All mineral acids are strong acids.
III. Phenolphthalein is a synthetic indicator.
IV. In neutralisation reaction, heat is always evolved.
V. If the soil is too basic, organic matter is added to it.
A. III, IV and V
B. I, III and V
C. I, III and IV
D. III only
Answer : A

Question. Study the given Venn diagram :

Points 1, 2, 3 and 4 represent

Answer : B

Question. Smita took a spoon of turmeric powder and made a paste by adding little water to it. She cut thin stripes of a paper and applied this paste on them. After drying she put few drops of given sample solutions (i)-(iv) on these strips. What would be the changes in the colour she observed?
(i) Amla juice
(ii) Lime water
(iii) Common salt solution
(iv) Baking soda solution

A. (i)-Yellow, (ii)-Red, (iii)-Yellow, (iv)-Red
B. (i)-Red, (ii)-Yellow, (iii)-Yellow, (iv)-Red
C. (i)-Red, (ii)-Red, (iii)-Yellow, (iv)-Yellow
D. (i)-Yellow, (ii)-Yellow, (iii)-Red, (iv)-Red
Answer : A

Question. The properties of substances X, Y and Z are given as :
X : Gas, transparent, colourless
Y : Solid, translucent, insulator
Z : Liquid, opaque, edible
X, Y and Z are respectively
A. Water vapour, petrol and mercury
B. Fog, frosted glass and muddy wate
C. Oxygen, butter paper and milk
D. Chlorine, glass jar and water.
Answer : C

Question. Match the given chemical reactions with the products listed in the box and select the correct option from the given codes.
(i)-CaO; (ii)-Mg(OH)₂; (iii)-NO₂ (iv)-Cu
(v)-MgCl₂; (vi)-O₂; (vii)-Fe₂O₃; (viii)-CaCO₃
P. Mixing magnesium oxide with water
Q. Brown deposit on iron nail kept in copper sulphate solution
R. Carbon dioxide is passed through lime water
S. Absorption of ultraviolet radiations by ozone.
A. P-(v), Q-(vii), R-(i), S-(vi)
B. P-(iv), Q-(ii), R-(i), S-(iii)
C. P-(ii), Q-(iii), R-(viii), S-(vii)
D. P-(ii), Q-(iv), R-(viii), S-(vi)
Answer : D

26. Study the given flowchart carefully.

P, Q, R and S are respectively
A. Salt, sawdust, iron dust, camphor
B. Sawdust, iron dust, camphor, salt
C. Iron dust, camphor, sawdust, salt
D. Camphor, iron dust, sawdust, salt.
Answer : D

Question. Kunal has classified a few processes as shown in the given table

The processes which are classified incorrectly are
A. II, IV and V only
B. III and V only
C. I, II, IV and V only
D. All of these.
Answer : C

Question. During the science activity, class teacher arranged the test tubes as shown in the figure and asked students to predict the effect of various indicators on the given solutions.

Which of the following statements are correct?
I. Turmeric solution will turn red in test tubes 1 and 4.
II. Methyl orange will turn yellow in test tubes 1 and 3.
III. China rose indicator will turn dark pink in test tube 2.
IV. Blue litmus solution will turn red in test tubes 1 and 4.
A. I and IV only
B. I, II and IV only
C. II and III only
D. None of these
Answer : C

Question. Refer to the given figure and select the correct option.

A. Joint X is similar to joint Y whereas joint W is similar to joint Z.
B. Joints U and V are fixed joints where bones do not show movement.
C. Joints Y and Z allow movement in only one plane, i.e., either back and forth or up and down.
D. None of these
Answer : C

Question. Refer to the given figure and select the correct option regarding P, Q, R, S and T.

A. In pea, R is modified into tendril to give support whereas in Venus flytrap, S is modified to catch insects.
B. R is modified into spines to prevent water loss whereas S performs photosynthesis in Opuntia.
C. T is modified to store food in turnip and ginger whereas outer covering of P is edible in cardamom.
D. Q is modified to store food in cabbage, broccoli and lettuce.
Answer : B

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

A. Plant P derives nutrition from the host plant with the help of haustoria and possesses hygroscopic roots which absorb moisture directly from atmosphere.
B. Plant Q possesses broad thin leaves with superficial stomata.
C. Plant R possesses special leaf modifications to catch and digest insects.
D. Plant S possesses stilt roots which help in aeration.
Answer : C

Question. Refer to the given food web.

Which of the following holds true regarding this?
A. There are four primary consumers and one secondary consumer in the given food web.
B. There are two herbivores and two carnivores in the given food web.
C. Snake is serving as both primary and secondary consumer in this food web.
D. If grasshopper and beetle population is removed from this community then frog population will be affected negatively.
Answer : D

Question. Two friends Rohan and Ravi visited a general physician for their respective diseases. Doctor examined them and prepared a chart as shown below to keep a record of their illness.

Refer to the given chart and select the correct option regarding this.
A. Rohan is suffering from deficiency of a fat soluble vitamin which helps in formation of bones and teeth.
B. Ravi is suffering from deficiency of a mineral that is required for formation of haemoglobin that carries oxygen from lungs to body cells.
C. Rohan is suffering from deficiency of a mineral that also increases immunity against various diseases.
D. None of these
Answer : B

Question. Read the following statements carefully and select the option which correctly identifies the true (T) and false (F) statements.
(i) Synthetic fibres are the fibres that are made from chemicals.
(ii) Cashmere wool is obtained from cashmere rabbit.
(iii) Anthrax is an occupational disease caused by a bacteria Bacillus anthracis.
   (i)     (ii)   (iii)
A. T      F      T
B. F      F      T
C. T      T      F
D. F      T      T
Answer : A

Question. Farheen soaked some bean seeds in water overnight. Next morning she drained the water and kept the seeds moist till they started germinating. She boiled half of the seeds and then kept the germinating seeds in one thermos flask X and the boiled seeds in another thermos flask Y. She covered the mouth of both flasks with moist cotton wool. Then she inserted thermometers in both flasks and left them. What would be her observation after four hours?
A. Temperature of flask X increases because it has photosynthesising seeds.
B. Temperature of flask X increases because it has respiring seeds.
C. Temperature of flask Y increases because it has boiled seeds.
D. Both B and C
Answer : B

Question. Refer to the given dichotomous key.
I. (a) Fibre obtained from natural resources – Go to II
(b) Fibre obtained from chemicals – P
II. (a) Plant fibre – Go to III
(b) Animal fibre – Go to IV
III. (a) Fibre obtained from seeds of plants – Q
(b) Fibre obtained from stem of plants – R
IV. (a) Fibre obtained from mammal – S
(b) Fibre obtained from insect – T
Which of the following is incorrect regarding P, Q, R, S and T ?
A. P is a petroleum based fibre which does not absorb water readily.
B. Both fibres Q and S are obtained from their source organisms without harming them.
C. Q is separated from seeds by retting whereas R is separated from stems by ginning.
D. S can be obtained from the same animal again and again whereas T can be obtained from an animal only once in its lifetime.
Answer : C

Question. The given diagram shows percentage composition of gases P, Q, R and other gases present in air.

Which of the following statements is correct regarding gases P, Q and R?
(i) P can be fixed in soil by certain bacteria present in roots of leguminous plants.
(ii) P supports combustion whereas Q and R help in extinguishing fire.
(iii) Plants and animals release R in respiration whereas plants use Q in photosynthesis.
(iv) R entraps sun's heat and makes earth warm and hospitable.
A. (i) and (iv) only
B. (ii) and (iii) only
C. (i), (ii) and (iv) only
D. (iii) only
Answer : A

Question. Digestive juices were collected from three different regions of the alimentary canal. Drops of these juices were added to wells made in an agar of starch as shown below.

Answer : D

Question. Refer to the given diagram which shows a test tube containing blood
with its components arranged in layers (X, Y and Z) after it had been stirred thoroughly for 5 minutes in a process known as centrifugation.

(In centrifugation, the heavier components sink to the bottom of the test tube while the lighter components rise towards the surface). Now, select the correct statement regarding layers X, Y and Z.
A. Layer X represents blood plasma, layer Y is chiefly constituted by red blood corpuscles whereas layer Z contains blood platelets.
B. Layer Y would be absent or greatly reduced in case of blood sample obtained from person whose blood does not clot easily.
C. Layer Z is chiefly composed of water, enzymes, hormones etc.
D. Layer X possesses haemoglobin responsible for oxygen transport in human body.
Answer : B

Question. Shruti planted many plants belonging to two separate species X and Y in her garden. She watered them regularly and took proper care of them. Plants of both species flowered. After sometime Shruti noticed that only plants belonging to species X yielded fruits whereas fruit setting was absent in plants of species Y. What could be the probable reason for this?
A. Plants of species X are wind pollinated but plants of species Y are insect pollinated.
B. Species X is dioecious whereas species Y is monoecious.
C. Plants of species Y present in Shruti's garden are dioecious male plants.
D. Plants of species X bear only unisexual female flowers whereas plants of species Y bear bisexual flowers.
Answer : C

Question. The leaves of a green bean plant were exposed to carbon dioxide containing the radioactive isotope of carbon 14C for few hours in sunlight. 

A section of the plant's stem was then immediately obtained and placed on an X-ray film that blackens where exposed to radioactivity. The following diagrams show the cross-section of the stem, and the resulting autoradiograph. Why is structure P shown radioactive?
A. P transported radioactive carbohydrates from leaves to other plant parts.
B. Radioactive carbon dioxide gets dissolved in cell sap and is transported along with water and minerals by structure P.
C. The radioactive carbon is incorporated only in the tissues constituting structure P.
D. None of these
Answer : A

Question. Refer to the given Venn diagram and identify P, Q, R and S.

A. P – Paramecium, Q – Scoliodon, R – Spiny ant eater, S – Lung fish
B. P – Lion tailed macaque, Q – Salmon, R – Dolphin, S – Platypus
C. P – Earthworm, Q – Rohu, R – Blue whale, S – Frog
D. P – Amoeba, Q – Tadpole, R – Trout, S – Snake
Answer : C

Question. A handful of soil was mixed in water and left in a jar for some time. Different components of soil got segregated and formed layers, as shown in the given figure.

Select the correct option regarding layers X, Y and Z.
A. Soil sample having high amount of X than Y and Z is best suited for maize cultivation.
B. Soil sample having almost same amount of Y and Z and comparatively much less amount of X has highest percolation rate and water absorbing capacity.
C. Soil containing more amount of Z and very little X and Y is prominent in areas where Kangaroo rat and Acacia are commonly found.
D. The space between particles is very large in X however particles are small sized and compactly arranged in Y and Z.
Answer : C

Question. Read the given paragraph with few blanks. (i) body of birds reduces resistance offered by wind. Their (ii) are modified into wings which help them in flight. Birds have (iii) bones which make their body light. Birds are (iv) and maintain constant body temperature. (v) are attached to their lungs which serve as reservoirs of air. Birds maintain equilibrium in flight due to well developed (vi) of brain.
Select the option that correctly fills any 3 of these blanks.
A. (i) Spindle shaped, (ii) Hindlimbs, (vi) Cerebrum
B. (ii) Forelimbs, (iv) Homeothermic, (vi) – Cerebellum
C. (i) Radially symmetrical, (iii) Pneumatic, (v) Air sacs
D. (iv) Poikilothermic, (v) Air sacs, (vi) Cerebrum
Answer : B

Question. Read the given paragraph.
X, Y and Z are three methods of waste management. X requires action of biological agents whereas Y and Z are chemical processes. Both X and Y reduce the waste volume whereas Z makes the waste reusable.
Which of the following is incorrect regarding X, Y and Z ?
A. X enriches the soil with nutrients and helps in recycling of matter between living organisms and their environment.
B. Y generates gases and heat energy and is best suited for disposing toxic waste.
C. Z increases the demand and supply of fresh raw material and causes air and water pollution.
D. Saprophytes and detritivores play a major role in X.
Answer : C

ACHIEVERS SECTION

Question. Observe the given figure carefully and fill in the blanks by choosing an appropriate option

Answer : D

Question. Which of the following statements is correct for the given circuit diagram?

A. To convert the electrical energy into heat energy, only switch R should be closed.
B. Minimum number of switches needed to be closed for conversion of electrical energy to sound energy is two.
C. To convert the electrical energy to light energy, only switches S and Q should be closed.
D. If electrical energy is being converted to sound energy and heat energy, then conversion to light energy is also taking place.
Answer : D

Question. Refer to the given food web.

Answer : A

Question. Read the given paragraph where few words have been italicised.
Buccal cavity of humans contains two pairs of salivary glands which secrete digestive juices that help in digestion of proteins present in food. From here food enters stomach where digestion of mainly fats takes place. As this semi-digested food enters small intestine complete digestion of food occurs. Small intestine receives bile juice from pancreas which digests fats.
Most absorption of water occurs in large intestine. 
Select the correct option regarding this.
A. Two should be replaced by four whereas proteins should not be replaced as it is correctly mentioned.
B. Fats should be replaced by carbohydrates and pancreas should be replaced by liver.
C. Digests should be replaced by emulsifies.
D. Large should be replaced by small.
Answer : C

Question. Refer to the given diagram showing a natural cyclic process.

Which of the following holds true regarding it ?
A. Deforestation will decelerate process V.
B. Process I occurs at a high rate in a rainforest and is absent in deserts whereas process III is involved in dew formation.
C. The physical state of water at X is liquid and that at Y is gaseous.
D. Both processes II and IV involve conversion of one physical state of water into another
Answer : A