CBSE Class 7 Science NSO Olympiad MCQs with Answers Set B

LOGICAL REASONING

Question. Which would be the ascending order of the following?
1. Trillion 2. Thousand
3. Billion 4. Hundred
5. Million
A. 1, 2, 3, 4, 5
B. 1, 5, 3, 2, 4
C. 4, 2, 3, 5, 1
D. 4, 2, 5, 3, 1
Answer : D

Question. If the days of the week are replaced by every alternate letter of the English alphabet, with Wednesday replaced by E, Thursday by G and so on, then fifth day beginning from Friday will be shown by which of the following ?
A. E
B. I
C. O
D. Q
Answer : D

Question. A set of figures carrying certain characters is given. 
Assuming that the characters in each set follows a similar pattern, find the missing character.

A. 5
B. 6
C. 4
D. 3
Answer : C

Question. Three of the following four are alike in a certain way and hence form a group. Which is the one that does not belong to that group?
A. 1331
B. 2197
C. 3375
D. 4913
Answer : C

Question. Ashu, Bindu and Sonu are standing at the corners of an equilateral triangle as shown in figure. They all run along the sides in clockwise direction and stops after covering 1½ sides. Now which of the following statements is true?

A. Bindu is to the west of Sonu.
B. Ashu is to the south-east of Bindu.
C. Ashu is to the south-west of Sonu.
D. Sonu is to the north-west of Ashu.
Answer : D

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

Answer : D

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

Which region represents the backward uneducated people those are employed?
A. 14
B. 5
C. 7
D. 11

Answer : B

Question. Find the mirror image of the Fig. (X), if the mirror is placed vertically to the right.

Answer : C

Question. A man, pointing to a photograph, says, "The lady in the photograph is my nephew's maternal grandmother."
How is the lady in the photograph related to the man's sister who has no other sister?
A. Sister-in-law
B. Mother-in-law
C. Mother
D. Data inadequate
Answer : C

Question. How many cubes are there in the pile?

A. 95
B. 114
C. 100
D. 115
Answer : B

Question. At the end of a business conference, all the ten people present shake hands with each other once.
How many handshakes will there be altogether?
A. 20
B. 45
C. 55
D. 90
Answer : B

Question. If the alphabets are written in reverse order after interchanging alphabets from 'C to M' with those from 'P to Z' respectively, which letter would be midway between E and S in the new order ?
A. Z
B. Y
C. N
D. X
Answer : B

Question. How many triangles are there in the given figure?

A. 21
B. 23
C. 25
D. 22
Answer : A

Question. Which of the following figures will continue the given series ?

Answer : C

Question. Select a figure from the options in which Fig. (X) is exactly embedded as one of its part.

Answer : C

SCIENCE

Question. The diagram shows the velocity against time graph for the motion of a body. What is its displacement in the first 5 s?

A. 11 m
B. 13 m
C. 7.5 m
D. 9 m
Answer : D

Question. The melting point of a substance is 125°C, and its boiling point is 305°C. At 105°C, the substance is in the ________ .
A. Solid state
B. Liquid state
C. Gaseous state
D. Solid and liquid state
Answer : A

Question. The given diagram shows a series of images of a moving ball captured by a camera.

The ball was moving at a constant velocity and the images were taken at a constant rate of 10 per second.
What is the speed of the ball?
A. 30 m s^–1
B. 20 m s^–1
C. 45 m s^–1
D. 15 m s^–1
Answer : A

Question. A camera makes use of a converging lens to produce an image. If the camera captures a distant object, then which of the following sets of characteristics of image is correct?
A. Virtual, inverted, same size
B. Real, inverted, diminished
C. Real, upright, same size
D. Virtual, upright, diminished
Answer : B

Question. Bulb 1 and bulb 2 are connected in series as shown in the given figure (i).

What will happen to the brightness of these two bulbs when a third identical bulb is connected across bulb 1 as shown in the given figure (ii)?
    Brighter        Brighter
B. Brighter         Dimmer
C. Dimmer         Dimmer
D. Dimmer         Brighter
Answer : D

Question. An old man moves along a semi-circular track of radius 40 m during morning walk. If he starts at one end of the track and reaches the other end, the distance covered and displacement of the man with respect to the starting point are respectively _____ .
A. 120 m, 40 m
B. 126 m, 80 m
C. 110 m, 60 m
D. 50 m, 120 m
Answer : B

Question. A sphere, a cube and a thin circular plate, all of same material and same mass, are initially heated to same high temperature. Then the ________ .
A. Sphere will cool fastest and cube the slowest
B. Plate will cool fastest and sphere the slowest
C. Cube will cool fastest and sphere the slowest
D. Sphere will cool fastest and plate the slowest
Answer : B

Question. Rohan blows air with a straw near the opening of another straw which has its other end in a soft drink bottle as shown in the given figure. The level of the soft drink in the straw rises up as soon as air is blown over its open end. Which one of the following best explains the reason for rise in level of the drink?

A. Blowing of air increases pressure over the open end of straw.
B. Blowing of air decreases the pressure on the surface of soft drink in the bottle.
C. Blowing of air decreases pressure over the open end of straw.
D. Blowing of air increases the pressure on the surface of soft drink in the bottle.
Answer : C

Question. If the strength of the current flowing through a coil is increased, then which of the following statements is true regarding it?
A. Strength of the magnetic field decreases.
B. Strength of the magnetic field increases.
C. Amount of heat generated due to resistance decreases.
D. Strength of the magnetic field remains constant
Answer : B

Question. Some changes are classified as given below :

Which of the above changes are incorrectly matched?
A. I, II, III and VI
B. I, III and V
C. II, IV and VI
D. All are correct.
Answer : B

Question. Observe the following experimental set-up carefully.

What conclusion can you draw?
A. Only air (dry) can cause rusting.
B. Air and water are needed for rusting.
C. Only water (air free) can cause rusting.
D. Data is insufficient to conclude anything.
Answer : B

Question. Yash wants to prepare lemonade for his mother. He has no idea about the quantity of water, salt, sugar and lemon to be added. Suddenly, he observes that no more salt or sugar can be dissolved in the amount of water he has taken.
Which of the following statements is not correct?
A. The solution obtained is saturated solution.
B. Yash can solve his problem by using large quantity of water.
C. By stirring well, more salt can be dissolved.
D. Some more sugar can be dissolved in solution by heating.
Answer : C

Question. Study the given flowchart and select the appropriate option.

Answer : A

Question. In the given reaction

Answer : D

Question. Kritika set-up the experiment as shown in the diagram.
She took three identical containers with ice and left them at different places.

After 10 minutes, she observed that lowest amount of water was present in
A. Set-up A
B. Set-up B
C. Set-up C
D. All set-ups contain equal amount of water.
Answer : A

Question. Match the problems given in Column-I with their remedies in Column-II and mark the correct option from the given codes.
      Column-I               Column-II
a. Indigestion        (i) Calamine solution
b. Bee sting          (ii) Calcium carbonate
c. Tooth decay      (iii) Milk of magnesia
d. Wasp sting       (iv) Vinegar
A. a-(iii), b-(iv), c-(ii), d-(i)
B. a-(iii), b-(i), c-(ii), d-(iv)
C. a-(i), b-(iii), c-(iv), d-(ii)
D. a-(iv), b-(i), c-(iii), d-(ii)
Answer : B

Question. The given diagram was drawn to show the sequence of events associated with acid rain pollution but was mistakenly left blank.

Complete the diagram with correct sequence of events from the following list.
a. Sulphur dioxide rises into the atmosphere
b. Acid rain falls
c. Fish die in acidified lakes
d. Discarded car batteries leak acid
e. Fuel combustion in power stations
f. Ozone is produced in power stations
g. Pollutant combines with water vapour
A. e, d, a, f, c
B. e, a, g, b, c
C. d, f, g, b, c
D. c, g, f, e, b
Answer : B

Question. Siddhi put a balsam plant in a beaker of black ink as shown below. After 3 days, she cut open a section of the stem of the plant and observed it.

Answer : B

Question. The given graph shows the percentage of undigested  carbohydrates, proteins and fats through successive parts of the human alimentary canal.

Why does the percentage of undigested carbohydrates remain constant in part X?
A. All the starch has been digested and only other carbohydrates remain.
B. Protease at part X prevents the salivary amylase from acting on starch.
C. The acidic conditions of part X prevent salivary amylase from acting on starch.
D. All the carbohydrates have been digested before reaching part X.
Answer : C

Question. The rate of water uptake by a Hibiscus plant kept outdoors was recorded over a few days. The graph below shows the results obtained.

Which of the following does not explain why water uptake was higher at noon than midnight on all the three days?
A. Transpiration pull is stronger in high light intensity.
B. The rate of transpiration increases with temperature.
C. The occurrence of photosynthesis in the guard cells opens the stomata during the daytime.
D. Air is generally more humid in day time which increases the transpiration pull.
Answer : D

Question. Kanika noticed that her potted plant was not growing healthily. She put three earthworms into the pot. After a few weeks, she noticed that her plants looked healthier.
What could be the possible reason for this?
A. The earthworms ate up the pests in the soil.
B. The earthworms helped the plant to take in water.
C. The earthworms allowed the plant to make food faster.
D. The earthworms increased the air and nutrient content of the soil.
Answer : D

Question. Which conditions would result in the highest rate of movement of oxygen from the alveolus into the blood capillaries?

Answer : B

Question. Fish are adapted for swimming and their swimming speed depends on several factors such as shape of the fins, body etc. Keeping this in mind, arrange the following fish in order, starting from the fastest swimmer to the slowest.

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

Question. Garima carried out a fair test to find out the speed with which water passed through four different kinds of soil. She recorded her findings in the table below.

In which type of soil would you find the mangrove trees growing in?
A. P
B. Q
C. R
D S
Answer : C

Question. The given Venn diagram represents characteristics of three gases P, Q and R. In atmosphere, more than 3/4 part of air consists of R, about 1/4 part consists of P and a very minor fraction is composed of Q and other gases.

Select the incorrect option regarding the characteristics of X, Y and Z.
A. X – Support life on earth
B. Y – Inhibit combustion
C. Z – Form compounds that are components of acid rain
D. None of these
Answer : D

Question. Which of the following statements support(s) the fact that the upper surface of a leaf is usually greener than the lower surface?
(i) More chlorophyll is present on the upper surface to absorb more light.
(ii) There are more stomata present on the upper surface than the lower surface.
(iii) More sugar is formed on the lower surface.
(iv) The green leaves look greener under the hot Sun.
A. (i) only
B. (ii) and (iii)
C. (ii) and (iv)
D. (iv) only
Answer : A

Question. Read the following statements (i-iv) with blanks and select the option that correctly fills the blanks in any two of the statements.
(i) The process of unwinding the silk filaments from the cocoon and combining them together is called ________.
(ii) ________ is removal of fleece from animal.
(iii) ________ is the principle component of silk.
(iv) ________ straightens the woollen fibre and also removes residual dirt.
A. (i) Reeling, (ii) Sorting
B. (ii) Scouring, (iv) Carding
C. (iii) Fibroin, (iv) Carding
D. (i) Weaving, (iii) Fibroin
Answer : C

Question. The oxygen cycle is a delicately balanced process.
Which of these, however, can upset this balance?
A. Acid rain and ozone depletion
B. Deforestation and excessive burning of fuels
C. Excessive use of fertilizers and pesticides
D. Overpopulation and forestation
Answer : B

Question. The given passage is on the production of cotton fabric. It has some errors. One of which is highlighted for your reference. Select the number of errors in it, including the given error.
Cotton is a soft fibre that grows around the fruit of the cotton plant (cottonbolls). After maturing, cottonbolls are burst open, the seeds are then separated from the cotton fibres by shearing. This process was earlier done by machines, nowadays done by hands.
The raw cotton fibres are pulled apart and cleaned to remove all dust and impurities. This process is known as carding. The fibre is then cleaned, straightened and made into soft, untwisted fabrics. This process of making fabrics is known as spinning. A yarn is made from two sets of fabrics arranged together. This is done by knitting.
A. 4
B. 8
C. 10
D. 5
Answer : B

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

A. a-3; b-2, 5; c-5; d-1, 4
B. a-3, 6; b- 4; c-5; d-1, 2
C. a-3, 6; b-1, 2; c-4; d-5
D. a-4, 5; b-1; c-3, 6; d-2
Answer : B

ACHIEVERS SECTION

Direction (Q. No. a and b) : Refer to the given experimental set-up to answer the questions

Question a. What is the purpose of flask 2?
A. To dry the air entering flask 3 for oxygen
B. To test the air entering flask 3 for carbon dioxide
C. To test whether the gas produced by the insect contains carbon dioxide
D. To remove carbon dioxide from the air entering flask 3
Answer : B

Question b. Which of the following statements regarding this set-up is not true?
A. Any carbon dioxide found in flask 3 is produced by the insect.
B. Only the solution in flask 4 should show a visible change.
C. The insect will die after some time due to the lack of oxygen.
D. The purpose of flask 1 is to remove carbon dioxide from the air.
Answer : C

Question. A painter leans his back against a painted wall while looking into a 1 m long mirror at the opposite end of a rectangular room as shown in the given figure.''

How much of the painted wall can he see through the given mirror?

A. 1 m
B. 2 m
C. 6 m
D. 12 m
Answer : B

Question. A science teacher has arranged the following sets of test tubes.

    (i)    (ii)     (iii)   (iv)    (v)    (vi)
A. 2       4       3      4       1       3
B. 4       2       1      3       4       1
C. 1       3       2      4       1       3
D. 2       4       1      3       2       4

She asked the students to fill in the blanks by observing the above experimental set-up carefully.
(a) Turmeric solution turns red in test tubes  (i) and (ii) .
(b) China rose indicator turns dark pink in test tubes (iii) and (iv) .
(c) Phenolphthalein gives pink colour in test tubes (v) and (vi)
Answer : D

Question. The diagram below shows two plants of the same species. Refer to the diagram to answer the following questions.

(i) Which arrow indicates a process that would not lead to sexual reproduction ?
(ii) Which arrow represents a type of pollination that would result in greater adaptability of the particular species to potential environmental changes?
A. (i)-Y, (ii)-Z
B. (i)-Z, (ii)-X
C. (i)-Y, (ii)-X
D. (i)-X, (ii)-Y
Answer : C