CBSE Class 7 Science NSO Olympiad MCQs with Answers Set A

LOGICAL REASONING

Question. Four friends M, N, O and P are playing cards. If P faces towards North and M faces towards West, then who faces towards South?
A. O
B. N
C. P
D. Data inadequate
Answer : D

Question. Pointing towards a man, Radhika said, "His sister is my daughter's brother's mother." How is the man related to Radhika?
A. Brother
B. Father
C. Uncle
D. Grandfather
Answer : A

Question. Select the option which will replace the question mark in the given number series.
198, 194, 185, 169, ?
A. 92
B. 112
C. 136
D. 144
Answer : D

Question. Which of the following Venn diagrams represents the best relationship amongst "Men, Trees and Living beings"?

Answer : B

Question. Which of the following numbers will complete the given figure?

A. 90
B. 97
C. 107
D. 117
Answer : B

Question. Select a pair of figures from the options which has same condition of placement of dots.

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

Question. If the digits of a watch are replaced by every alternate letter in alphabets starting from 12, in the reverse order, i.e. 12 is replaced by A, 11 is replaced by C and so on, then at which letter would be the hour hand when it is 5:00 pm?
A. P
B. N
C. O
D. Q
Answer : C

Question. Count the number of rectangles in the given figure.

A. 20
B. 18
C. 16
D. 14
Answer : A

Question. Find the mirror image of the given Figure (X), if the mirror is placed vertically to the left.

Answer : B

Question. Arrange the given units in a meaningful sequence.
1. Hecto 2. Centi 3. Deca 4. Kilo 5. Deci
A. 1, 3, 4, 5, 2
B. 1, 5, 3, 4, 2
C. 2, 5, 3, 1, 4
D. 5, 2, 1, 4, 3
Answer : C

Question. Two positions of a dice are given below. Find the number at the bottom, when number 6 is at the top.

A. 1
B. 4
C. 5
D. Can't be determined
Answer : A

Question. 121 is related to 12 in the same way as 25 is related to _____.
A. 1
B. 2
C. 6
D. 7
Answer : C

Question. A bird shooter was asked how many birds he had in his bag. He replied that there were all sparrows but six, all pigeons but six, and all ducks but six.
How many birds did he have in all in his bag?
A. 9
B. 18
C. 27
D. 36
Answer : A

Question. Which of the following is exactly in the middle of the 17th from the right end, and 18th from the left end, in the given arrangement?
3 D 6 $ C 4 E 8 # N 5 F 1 A P ★ 9 M @ K 2 B % 7 H U
A. A
B. 1
C. F
D. %
Answer : A

Question. Which of the following options will complete the pattern in Figure (X)?

Answer : C

SCIENCE

Question. A ray of light parallel to the floor strikes a plane mirror, which is inclined at an angle 40° as shown in figure. What is the angle of reflection?

A. 40°
B. 80°
C. 50°
D. 90°
Answer : C

Question. When you heat a system, its temperature _____.
A. Always increases
B. Sometimes decreases
C. May stay the same
D. Always goes up or down, depending on the heat
Answer : C

Question. Two boys, P and Q are running along the same path. P is 10 m ahead of Q initially. However, Q catches up with P, after running 50 m. Assuming that both boys are running at a constant speed, what is the ratio of the speeds of P and Q?
A. 6 : 5
B. 5 : 6
C. 4 : 1
D. 4 : 5
Answer : D

Question. The given figure shows a circuit which contains two identical lamps. When the switch is closed, which of the following statements best describes, what happened to lamps P and Q?

A. P is brighter than before, but Q does not light up.
B. P does not light up, but Q is brighter than before.
C. Both P and Q are brighter than before.
D. P and Q both will not light up.
Answer : B

Question. Two magnets, P and Q attract four soft iron bars, W, X, Y and Z at their poles, as shown in the given figure. What will happen to the iron bars, when the two magnets move towards each other, and attract each other ?

A. Nothing will happen.
B. X and Y will drop off.
C. X and Y will repel away each other.
D. W and Z will attract X and Y respectively.
Answer : B

Question. A laboratory thermometer gave the reading of –1°C and 99°C when inserted into melting ice and boiling water respectively, both at standard atmospheric pressure. What is the error when the same thermometer is used to measure the difference between two arbitrary temperatures?
A. –1°C
B. 1°C
C. 0°C
D. 2°C
Answer : C

Question. Metal pots are often made shiny on surface outside especially on the top and side and that makes sense thermally because this ______.
A. Conducts heat better
B. Radiates less energy out from the pot
C. Lowers the loss due to conduction
D. Appreciably decreases convection losses
Answer : B

Question. Komal and Kavita start at one end of a street (the origin), run to the other end, and then head back. On the way back, Komal is ahead of Kavita. Which of the given statements is correct, regarding the distance covered and the displacement from the origin at the moment?
A. Kavita has run a greater distance, but her displacement is less than that of Komal.
B. Kavita has run a greater distance and her displacement is greater than that of Komal.
C. Komal has run a greater distance, but her displacement is less than that of Kavita.
D. Komal has run a greater distance and her displacement is greater than that of Kavita.
Answer : C

Question. During the formation of rain, when water vapours change back to liquid in the form of rain drops, _____.
A. Heat is absorbed
B. Heat is released
C. Heat is first absorbed, and then released
D. There is no exchange of heat
Answer : B

Question. Observe the following experimental set-up carefully.

Identify liquid (X) in the test tube, residue (Y) left in the beaker, process (Z) involved

Answer : D

Question. Read the given statements and select the correct option.
Statement 1: Acid rain causes damage to buildings, historical monuments, plants and animals.
Statement 2: Air pollutants such as carbon dioxide, sulphur dioxide and nitrogen dioxide dissolve in rain drops to form carbonic acid, sulphuric acid and nitric acid respectively.
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. Both statements 1 and 2 are false.
Answer : A

Question. Reyansh placed three different types of glasses in front of letters as shown below :

Which of the following observations is correct?
A. Glass I is transparent and unclear.
B. Glass I is translucent and clear.
C. Glass II is opaque and frosted.
D. Glass III is translucent and frosted.
Answer : D

Question. Preeti has collected some items from her kitchen :
i. Amla ii. Baking soda
iii. Tamarind iv. Soap
v. Lime water vi. Common salt
vii. Sugar
She classified them as acidic, basic and neutral substances. Which of the following classification is correct?

Answer : D

Question. A science teacher arranged the following sets of test tubes and added different indicators to the solutions.

She asked the students to find out the incorrect result from the following.
A. Test tubes 1 and 3 turn turmeric solution to red.
B. Test tubes 2 and 4 turn China rose indicator to green.
C. Methyl orange turns yellow in test tubes 1 and 3.
D. Phenolphthalein remains colourless in test tubes 2 and 4.
Answer : B

Question. Some examples of changes are given below :
a. Cutting a log of wood into pieces.
b. Breaking down of ozone.
c. Melting of glaciers.
d. Lime water turns milky.
e. Digestion of food.
f. Punching a hole in a paper.
Classify the above changes into
I. Irreversible physical change
II. Chemical change
III. Reversible physical change
A. I - a, f         II - b, d, e       III - c
B. I - a, b, e     II - d, f           III - c
C. I - a            II - b, d           III - c, e, f
D. I - f             II - c, e           III - a, b, d
Answer : A

Question. 50 mL of water at 25°C was poured into each of the three containers as shown in the given figure.
The containers were then left in a closed room.

Answer : C

Question. Which of the following statements is/are true (T) or false (F) regarding nutrition in organisms?
(i) Photosynthesis also occurs in leaves having colour other than green.
(ii) The process of photosynthesis first produces a simple carbohydrate called glucose which then gets converted into a complex carbohydrate called starch.
(iii) Cuscuta is a yellow-coloured plant but it can synthesize its own food by photosynthesis.
(iv) In a symbiotic association, Rhizobium bacteria derive their nutrition from fungus.
    (i)    (ii)    (iii)     (iv)
A. F      T       T        T
B. T      T       T        F
C. F     F        F       T
D. T     T        F       F
Answer : D

Question. Read the given passage.
The water-bearing layer of the earth called P is made up of two components Q and R .
The top level of layer P is called S .
When too many tubewells are used in an area, the level of S in that area goes down.
Select the correct sequence of words to fill up the blanks in the above passage.

Answer : D

Direction : Read the given passage carefully and answer Q. No. 34 and 35.
The phenomenon in which a bird or other animal moves from one place to another in one season, and returns again in a different season is called migration. It is an adaptation to escape the harsh conditions of their normal habitat so as to survive.

Question. The (i) flies from its native place in Russia to places like (ii) in Rajasthan and (iii) in Haryana during a particular season. It stays in India for a few months and then goes back in (iv) season. The general name given to birds like these is (v) birds. 
Select the correct sequence of words to fill up the blanks in the above passage.

Answer : B

Question. Which of the following is the probable method these migratory birds use to travel to the same place year after year?
A. They have built-in sense of direction and probably use land-marks to guide themselves.
B. They are guided by the position of the sun during the day and by the position of stars at night.
C. They use the magnetic field of earth to find the direction so as to reach the same place.
D. All of these
Answer : D

Question. A teacher showed the following plants to students and asked them to write their methods of reproduction

Given below are answers written by the students :
Student P : W, X and Y propagate vegetatively through stem.
Student Q : W and X are rhizomes which propagate vegetatively through roots.
Student R : Z is called bulbil which propagates vegetatively through stem.
Student S : Y vegetatively propagates through roots.
Which student(s) wrote the correct answer?
A. Students P and S
B. Only Student S
C. Students Q and R
D. Only Student Q
Answer : B

Question. Refer to the given flow chart showing the characteristics P, Q and R which are present in some animals and absent in others.

Identify P, Q, R and select the correct option.

Answer : C

Question. Match column I with column II and select the correct option from the codes given below.
           Column - I             Column - II
(a) Clothing material            (i) Nylon
(b) Twisted fibre                  (ii) Fabric
(c) Synthetic fibre               (iii) Yarn
(d) Animal fibre                   (iv) Cotton
(e) Plant fibre                      (v) Silk
A. (a) - (i), (b) - (ii), (c) - (iii), (d) - (iv), (e) - (v)
B. (a) - (ii), (b) - (iii), (c) - (v), (d) - (i), (e) - (iv)
C. (a) - (ii), (b) - (iii), (c) - (i), (d) - (v), (e) - (iv)
D. (a) - (i), (b) - (iv), (c) - (iii), (d) - (ii), (e) - (v)
Answer : C

Question. Which of the following statements best describe the organism growing on the given piece of bread?
(i) It belongs to flowering plants.
(ii) It reproduces by spores.
(iii) It is a chlorophyllous organism.
(iv) It prepares its own food.
(v) It obtains food from dead and decaying organic matter.
A. (ii), (iii) and (iv)
B. (i), (ii) and (v)
C. (ii) and (v)
D. (iii) and (iv)
Answer : C

Question. The given diagram shows blood circulation pathway in the heart.
Which of the following correctly shows the relative amount of oxygen and carbon dioxide at P, Q, R and S?

     More CO₂       More O₂
A. R                     P, Q, S
B. Q and R          P and S
C. S                     R
D P and Q            R and S
Answer : D

Question. Which of the following statements are correct regarding the given animals?

(i) Both X and Y possess streamlined body and webbed feet.
(ii) Both are good swimmers.
(iii) Y has a thick layer of fat under its skin with fur on its body, while X has thick skin and a layer of fat under its skin.
(iv) Both live together in large numbers and huddle together to keep themselves warm.
(v) Y has very strong sense of smell unlike X.
A. (ii), (iii) and (iv)
B. (i), (ii), (iii) and (iv)
C. (ii), (iii) and (v)
D. (i) and (iv)
Answer : C

Question. Jayesh placed 3 potted plants in an airtight glass tank as shown in the given diagram.

If he placed the set-up in a dark cupboard for a few hours, what would happen to the limewater, after a few hours?
A. It would turn dark blue.
B. There would be slightly less limewater left.
C. It would turn milky.
D. There would be no change.
Answer : C

Question. Refer to the given figures and answer the question that follows.

What are the main functions of X, Y and Z?

Answer : D

Question. Given below are the four food components (P-S) and their corresponding sources
P – meat, fish, eggs
Q – butter, ghee, margarine
R – bread, biscuits, potatoes
S – amla, tomato, orange
Select the incorrect statement regarding them.
A. Deficiency of P causes Marasmus in children and Kwashiorkor only in adults.
B. Amongst P, Q, R and S, 1 gram of Q produces the maximum energy.
C. Excess of R gets stored in body cells, and is used for production of energy, whenever required.
D. Deficiency of S leads to a disease, in which gums swell up and bleed.
Answer : A

Question. Study the given diagram carefully. A pump containing 50 cm³ of air is connected to the glass jar. The capacity of the jar is 200 cm³ and it contains 200 cm³ of air.
The plunger is pushed all the way into the pump and all the air from the pump goes into the jar. What will be the volume of air in the jar now?

A. 250 cm³
B. 200 cm³
C. 50 cm³
D. Cannot be calculated
Answer : B

ACHIEVERS SECTION

Question. A fish sees the face of a scuba diver through a thin bubble, as shown in figure.

Compared to the face of the diver, the image seen by the fish will be _____.
A. Smaller and erect
B. Smaller and inverted
C. Larger and erect
D. Cannot predict
Answer : A

Question. Fill in the blanks by observing the following chemical process.

The above process becomes faster when humidity is a and can be prevented by applying a coat of b , or by depositing a layer of a metal like c on iron.

Answer : C

Question. A leaf litter community has woodlice as primary consumers and centipedes and millipedes as secondary consumers. The given graph shows the changes in the population of woodlice over a period of time. Which of the following is the incorrect possibility, as per given graph?

A. The number of centipedes in the habitat increases at point X.
B. There is an increase in the quantity of dead leaves in the habitat at point Z.
C. The number of millipedes in the habitat decreases at point X.
D. There is a shortage in the quantity of dead leaves in the habitat at point X.
Answer : C

Question.

The given figure shows the longitudinal section of two flowers of the same type. Study the following statements with reference to the given figure. 
(i) Z and U show self pollination, whereas Y shows cross pollination.
(ii) W, X and Z show transfer of pollen grains that will result in fruit formation.
(iii) Z shows self pollination, while X shows cross pollination.
(iv) X and Z show pollination that will result in fruit formation.
(v) W, X and Y show cross pollination.
Which of the given statements are true or false?
A. (i) and (iv) are true; (ii), (iii) and (v) are false.
B. Only (v) is true; rest are false.
C. (i), (ii), (iii) and (v) are true; (iv) alone is false.
D. (i), (ii) and (v) are false; (iii) and (iv) are true.
Answer : D

Question. Refer to the given graph which shows the effect of pH on the activities of three enzymes, X, Y and Z.

The three enzyme samples, X, Y and Z are taken from which parts of the human alimentary canal?

Answer : D